Patent Description:
Medical laser systems are used for a variety of surgical procedures. These procedures may include dusting and/or fragmentation of stones in the kidney, the bladder, and/or the ureter. Medical laser systems are also used to create incisions and to ablate and/or coagulate soft tissues, such as, but not limited to, the prostate. Surgical lasers output from medical laser systems have small laser pulse wavelengths, e.g., approximately <NUM>, and are invisible to the naked eye, e.g., medical lasers having mid-infrared wavelengths. Thus, it is necessary to use a visible alignment laser beam to align the medical laser system.

Conventional alignment procedures for medical laser systems are time consuming, with alignment of laser cavities and/or mirrors generally taking about one to two days to complete. One problem with conventional alignment techniques results from the use of laser pulses generated from the laser cavities, which has safety risks and which can cause damage to optics. Another problem associated with conventional alignment techniques is the use of a thermal paper during alignment. The use of thermal paper is necessary for these conventional systems since the alignment is not accurate, and thermal paper aids in correcting this accuracy. When the output beam is shot through the thermal paper, however, particles are generated which can contaminate and cause damage to the optics. <CIT> discusses a laser system includes a first cavity to output a laser light along a first path, a first mirror to receive the laser light from the first cavity, and redirect the laser light along a second path that is different than the first path, a beam splitter removably located at a first position on the second path, a beam combiner removably located at a second position on the second path, and an alignment device having first and second alignment features.

According to an aspect, a laser system includes a first laser cavity configured to output a laser light along a first path, a first mirror configured to receive the laser light from the first laser cavity, and redirect the laser light along a second path that is different than the first path, a second mirror configured to receive the laser light from the first mirror, and redirect the laser light along a third path that is different than the first path and the second path, a beam splitter located at a first position on the third path, a beam combiner located at a second position on the third path, and a coupling lens assembly, the coupling lens assembly including a lens located at a third position on the third path, wherein the coupling lens assembly is configured to move the lens in x-, y-, and z-directions.

The coupling lens assembly may include an outer housing configured to house a base frame, a stage plate, and a lens holder configured to support the lens, wherein the base frame, the stage plate, and the lens holder may move relative to each other.

The stage plate may include a pair of sidewalls, wherein a portion of the lens holder may be disposed between the pair of sidewalls, and wherein the lens holder may move toward one and the other of the pair of sidewalls.

The base frame may include a top wall and a bottom, wherein a portion of the stage plate may be disposed between the top wall and the bottom wall, and wherein the stage plate may move toward one and the other of the top wall and the bottom wall.

The laser system may further include a plurality of screw members to move the base frame, the stage plate, and the lens holder.

The laser system may further include at least one biasing member to bias the stage plate in a distal direction.

The laser system may further include a plurality of locking members to lock a position of the base frame, the stage plate, and the lens holder.

The base frame, the stage plate, and the lens holder may move independently.

The laser system may further include a plurality of first alignment members, wherein each of the plurality of first alignment members may include an opening, and wherein one first alignment member from the plurality of first alignment members may be disposed on the third path distal to the second mirror, and wherein another first alignment member from the plurality of first alignment members may be disposed on the third path proximal to the second mirror.

The laser system may further include an aiming laser generator, wherein the aiming laser generator may deliver an aiming laser to the beam combiner, wherein a portion of the aiming laser may pass through the beam combiner along a fourth path, and wherein the aiming laser generator may be aligned when the aiming laser passes through the opening in at least two first alignment members from the plurality of first alignment members arranged on the fourth path.

The laser system may further include a pair of second alignment members, each of the second alignment members may have an opening, wherein each of the second alignment members may be attached to the first laser cavity on the first path.

A laser generating rod may be removed from the first laser cavity before the second alignment members are attached to the first laser cavity.

The laser generating rod may be disposed on a first longitudinal axis when the laser generating rod may be attached to the first laser cavity, and wherein the opening in each of the second alignment members may be disposed on the first longitudinal axis.

The laser system may further include an output fiber to deliver a laser energy from the laser system to a target.

An alignment laser beam may be directed into the laser system from a distalmost end of the third path.

According to another aspect, a method for aligning a laser system includes delivering an alignment beam through a lens, wherein the lens is supported by a coupling lens assembly, and adjusting the coupling lens assembly to move the lens in an x-, y-, and z-direction such that the alignment beam passes through an opening in a first alignment feature positioned at a first location and through an opening in a second alignment feature positioned at a second location, onto a first mirror contained within the laser system.

The method may further include removing a laser rod from a laser cavity of the laser system, attaching a third alignment feature and a fourth alignment feature to the laser cavity, wherein each of the third alignment feature and the fourth alignment feature may include an opening, removing one of the first or second alignment features from the laser system, and adjusting one or more of the first mirror, a second mirror, and a third mirror such that the alignment beam passes through the openings in both the third alignment feature and the fourth alignment feature, onto a fourth mirror at a proximal end of the laser cavity.

The method may further include adjusting the third mirror, located at a distal end of the laser cavity, and the fourth mirror such that the aiming beam is reflected from the fourth mirror through the opening in one of the third alignment feature or the fourth alignment feature.

According to yet another aspect, a method for aligning a laser system having a first laser cavity includes delivering an aiming into the laser system via a lens, wherein the lens is supported by a coupling lens assembly, moving the lens in one or more of the x-, y-, or z-directions such that the aiming laser impinges on a first mirror, and moving the first mirror, a second mirror, and a third mirror such that the aiming laser beam passes through openings in a plurality of alignment devices and impinges on a fourth mirror at a proximal end of a laser cavity.

The method may further include delivering a second aiming laser to the laser system onto a coupler, wherein a first portion of the aiming light passes through the coupler along a first path, and wherein a second portion of the aiming light, different from the first portion, is reflected by the coupler along a second path adjusting a position of the aiming laser such that the first portion of the aiming light passes through openings in a pair of alignment devices disposed along the first path.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and, together with the description, serve to explain the principles of the disclosed embodiments.

Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the features, as claimed. As used herein, the terms "comprises," "comprising," "having," "including," or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such a process, method, article, or apparatus. In this disclosure, relative terms, such as, for example, "about," "substantially," "generally," and "approximately" are used to indicate a possible variation of ±<NUM>% in a stated value or characteristic.

For ease of description, portions of the disclosed devices and/or their components are referred to as proximal and distal portions. It should be noted that the term "proximal" is intended to refer to portions closer to laser cavities of the laser device, and the term "distal" is used herein to refer to portions further away from the laser cavities of the laser device, e.g., toward an end of a laser fiber that outputs a laser energy. Similarly, extends "distally" indicates that a component extends in a distal direction, and extends "proximally" indicates that a component extends in a proximal direction. Additionally, terms that indicate the geometric shape of a component/surface refer to exact and approximate shapes.

<FIG> illustrates an exemplary embodiment of a medical laser system <NUM>. The medical laser system <NUM> includes one or more laser cavities 30a-30d (one laser cavity <NUM> shown in <FIG>), each laser cavity capable of outputting an output laser beam (or laser light). Each of the one or more laser cavities 30a-30d includes a high reflecting window 36a-36d at a proximal end, an output coupler window 32a-32d at a distal end, and a chromium thulium holmium-doped YAG (CTH:YAG) laser rod 34a-34d disposed between respective high reflecting windows 36a-36d and output coupler window 32a-32d. CTH:YAG lasers are lamp-pumped (flash-lamp-pumped) Ho:YAG lasers, having a pulse width in the range of approximates <NUM> microseconds to approximately <NUM>-<NUM> milliseconds. Wavelengths of the lasers are approximately <NUM>, and may have a highest pulse energy of greater than <NUM> Joules at a pulse width of one millisecond. CTH:YAG lasers may be efficiently operated at a repetition rate at less than or equal to approximately <NUM> Hertz, with a maximum average power for each laser cavity being approximately <NUM> Watts. To ablate tissue and create a high enough heat to destroy objects, such as kidney stones, it is necessary to increase the repetition rate by using multiple laser cavities, each laser cavity having a CTH:YAG laser rod (e.g., 34a-34d). Combining laser energy generated from each laser cavity may provide an overall repetition rate of up to approximately <NUM> Hertz, and an average maximum power of greater than <NUM> Watts. Ensuring the laser energy generated from each laser cavity is coupled into the fiber and reaches the target tissue facilitates generating these high-power outputs. Thus, it is important to properly align the laser cavities, mirrors, and other elements as described herein.

Each CTH:YAG laser rod 34a-34d generates an output laser beam for each of the cavities 30a-30d, which is directed to a corresponding relay mirror 20a-20d (e.g., first mirrors) along a laser path C. For example, the output laser beam is output from cavity 30a to mirror 20a; from cavity 30b to mirror 20b; from cavity 30c to mirror 20c; and from cavity 30d to mirror 20d, with each output laser beam traveling along corresponding laser paths C. Each output laser beam is reflected from a respective one of the relay mirrors 20a-20d to a Galvo mirror <NUM> (e.g., second mirror) along respective laser paths B. For example, an output laser beam is reflected from relay mirror 20a to Galvo mirror <NUM> along laser path B. Galvo mirror <NUM> reflects each output laser beam along a same optical path A (e.g., laser path A) to a beam splitter <NUM> and a beam combiner <NUM>. Galvo mirror <NUM> is configured to rotate about an axis to face each of relay mirrors 20a-20d and receive output lasers from each laser cavity 30a-30d. The beam combiner <NUM> combines the output laser beams from the one or more cavities 30a-30d and may further combine an aiming beam from an aiming beam source (e.g., an aiming beam source <NUM> in <FIG>). The combined laser beam is passed along laser path A to a coupling lens <NUM> of coupling lens assembly <NUM> (<FIG>). The coupling lens <NUM> couples the output laser beam and matches the output laser beam to an output fiber <NUM>, to be transmitted to a delivery location. Coupling lens <NUM> may be any material suitable for coupling the laser light to output fiber <NUM>, including but not limited to a sapphire. Coupling lens <NUM> may have a diameter of approximately <NUM>, but is not limited thereto.

To help ensure proper output and to help avoid damage to the medical laser system <NUM>, and injuries to the user and/or the patient, the medical laser system <NUM> may be calibrated prior to use. The calibration and alignment of the medical laser system <NUM> may help ensure that the output laser from the one or more laser cavities 30a-30d properly reflects off each mirror and are coupled through coupling lens <NUM> into the output fiber <NUM>. After the alignment using the procedures described herein, fine-alignments of medical laser system <NUM> may be reduced to finalize the alignment. The alignment procedures of the present disclosure also may help technicians and operators service laser systems in the field, without requiring the systems to be sent off-site for service, and/or may reduce the time for calibrating medical laser systems <NUM> before delivering these systems to customers.

According to an exemplary embodiment, coupling lens assembly <NUM> may be configured to move coupling lens <NUM> in the x-, y-, and z-directions during the alignment procedures to ensure proper alignment of the out laser beam. As shown in <FIG>, coupling lens assembly <NUM> includes a housing 100a, 100b to house a base frame <NUM>. Housing 100a, 100b may include a proximal-most portion 100a and a distalmost portion 100b connected via screws or other fastening devices. Proximal-most portion 100a may include a recess or cavity configured to receive base frame <NUM> and other elements of coupling lens assembly <NUM>. Distalmost portion 100b may be attached to proximal-most portion 100a after base frame <NUM> is inserted into the cavity of proximal-most portion 100a, thereby fixing base frame <NUM> within the cavity of housing 100a, 100b. A fiber ferrule <NUM>, which may attach to a proximal-most end of fiber <NUM> and which may connect fiber <NUM> to coupling lens assembly <NUM>, may be attached to a distal end of housing 100a, 100b. Fiber ferrule <NUM> may connect to a connector of fiber <NUM>, such as an SMA connector or other similar connector for connecting fiber <NUM> to coupling lens assembly <NUM>.

With reference to <FIG>, adjusting screws <NUM>, <NUM>, and <NUM> may cause elements of coupling lens assembly <NUM> to move, thereby causing coupling lens <NUM> to move in the x-, y-, and z-directions, respectively. The x-direction axis defines a horizontal direction, and the y-direction axis defines a vertical direction. Coupling lens <NUM> is generally circular in cross-section and is supported by a lens holder <NUM>. It will be understood that coupling lens <NUM> may be any shape suitable for coupling the output laser to fiber <NUM>. Lens holder <NUM> is generally rectangular in cross-section, but is not limited thereto. Lens holder <NUM> is disposed between two vertical walls 102a, 102b of a stage plate <NUM>. Walls 102a, 102b extend in a vertical direction. One of vertical walls 102a, 102b includes adjusting screw <NUM>. According to an example, adjusting screw <NUM> is provided within an opening of wall 102b and is configured to move relative to stage plate <NUM> along an x-axis. Adjusting screw <NUM> may move transverse to vertical walls 102a, 102b and may cause lens holder <NUM> to move relative to walls 102a, 102b, thereby moving lens <NUM> in the x-direction. For example, rotating adjusting screw <NUM> in a first direction (e.g., a clockwise direction) may cause lens holder <NUM> to move to the right along the x-axis, and rotating adjusting screw <NUM> in a second direction, opposite the first direction (e.g., a counterclockwise direction) may cause lens holder <NUM> to move to the left along the x-axis. Adjusting screw <NUM> may move the lens holder <NUM> (e.g., by pushing or pulling against lens holder <NUM> via a threaded connection), or adjusting screw <NUM> may cooperate with a biasing member (e.g., a spring), which may provide a biasing or urging force against lens holder <NUM> in a direction toward adjusting screw <NUM>.

Stage plate <NUM> is disposed between two horizontal walls 101a, 101b of base frame <NUM>. One of walls 101a, 101b includes adjusting screw <NUM>. According to an example, adjusting screw <NUM> is provided within an opening of wall 101a and is configured to move relative to base frame <NUM> along a y-axis. Adjusting screw <NUM> may move transverse to horizontal walls 101a, 101b, and may cause stage plate <NUM> to move relative to walls 101a, 101b, thereby moving stage plate <NUM>, lens holder <NUM>, and lens <NUM> in the y-direction. For example, rotating adjusting screw <NUM> in a first direction (e.g., a clockwise direction) may cause stage plate <NUM> to move downwards along the y-axis, and rotating adjusting screw <NUM> in a second direction, opposite the first direction (e.g., a counterclockwise direction) may cause stage plate <NUM> to move to upwards along the y-axis. Adjusting screw <NUM> may move stage plate <NUM> directly (e.g., by pushing or pulling against stage plate <NUM> via a threaded connection), or adjusting screw <NUM> may cooperate with a biasing member (e.g., a spring), which may provide a biasing or urging force against stage plate in a direction toward adjusting screw <NUM>.

Adjusting screw <NUM> and springs <NUM> (e.g., biasing members) may be used to position base frame <NUM> within housing 100a, 100b. Springs <NUM> may be positioned at a proximal end of base frame <NUM>, and adjusting screw <NUM> may be positioned at a distal end of base frame <NUM>. Springs <NUM> may urge or bias base frame <NUM> in a distal direction relative to housing 100a, 100b, and screw <NUM> may provide an opposing force in an opposite direction, i.e., in the proximal direction. Rotation of screw <NUM> may move screw <NUM> proximally and distally relative to housing 100a, 100b, which may allow base frame <NUM> to move proximally and distally (i.e., in the z-direction) relative to housing 100a, 100b. For example, rotating adjusting screw <NUM> in a first direction (e.g., a clockwise direction) may cause base frame <NUM> to move proximally along the z-axis, and rotating adjusting screw <NUM> in a second direction, opposite the first direction (e.g., a counterclockwise direction) may cause base frame <NUM> to move distally along the z-axis. Since base frame <NUM> is located within housing 100a, 100b, sidewalls of housing 100a, 100b may define a path along the z-axis along which base frame <NUM> may move, such that base frame <NUM> slides along the z-axis. Once the proper alignment of lens <NUM> is achieved, screws <NUM> and <NUM> may be tightened to maintain a position of <NUM>, <NUM>, and <NUM> within housing 100a, 100b. For example, screws <NUM> and <NUM> (<FIG>) may be provided on either side of base frame <NUM> in the x-direction and may secure a position of base frame <NUM> to housing 100a, 100b and/or a baseboard (not shown) of medical laser system <NUM>. Screws <NUM> are provided at opposite corners on a distal end face of lens holder <NUM> and may secure a position of lens holder <NUM> to stage plate <NUM> once an appropriate position of lens holder <NUM> is achieved. It will be understood that screws <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may be operated by hand, e.g., using a thumb and a forefinger, and/or screws <NUM>, <NUM>, <NUM> may include a recess to receive a tool, such as an end of a screwdriver or similar tool to cause rotational movement of screws <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> in their respective openings. The screw threads on each of screws <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may enable the rotational movement to result in translational movement of each screw <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. It will be understood that the screws described herein may be any fastening mechanism such as thumb screws, clamps, or any other fastening mechanism not to one of ordinary skill in the art.

A laser cavity <NUM>, which is an example of laser cavities 30a-30d, is illustrated in <FIG>. Laser cavity <NUM> includes a base plate <NUM>, a base <NUM> configured to support a mirror mount <NUM> for a reflecting window (e.g., reflecting windows 36a-36d of <FIG>) at a first end of base plate <NUM>, and a mirror mount <NUM> configured to support an output coupler window (e.g., output coupler 32a-32d of <FIG>) at an opposite end of base plate <NUM>. An insulating plate <NUM> may be positioned on a top surface of base plate <NUM> and between base <NUM> and mirror mount <NUM> in the proximal-distal direction. Proximal and distal end walls 306a, 306b, respectively, and sidewalls 307a, 307b may protrude from a top surface of insulating plate <NUM>. Walls 306a, 306b, 307a, 307b may ensure proper positioning of a laser pumping chamber <NUM>, which includes the CTH:YAG laser rod configured to generate each laser beam (e.g., laser rods 34a-34d in <FIG>). Laser pumping chamber <NUM> may be secured to insulating plate <NUM> via screws at proximal and distal ends. Screw openings (not shown) in insulating plate <NUM> which receive the screws securing laser pumping chamber <NUM> to insulating plate <NUM> may also receive screws for securing second alignment devices <NUM> (see <FIG>). As shown in <FIG>, laser pumping chamber <NUM> may be removed during calibration to position second alignment devices <NUM> (see, <FIG>) as will be described herein.

<FIG> illustrates a first alignment device <NUM> and an example position of first alignment device <NUM> (a proximal first alignment device 401a and a distal first alignment device 401b are shown in <FIG>) for aligning medical laser system <NUM>. First alignment device <NUM> may be an elongate member with a neck portion at one end (e.g., a top end as shown in <FIG>). The neck portion may allow a user to grasp first alignment device <NUM> using a thumb and a forefinger and may also inform the user which end (i.e., the end opposite the neck portion) is to be attached to the baseboard (not shown) of medical laser system <NUM>. An opening <NUM> is formed in first alignment device <NUM> and may allow laser light to pass therethrough during an alignment procedure. A diameter of opening <NUM> may be equal to or greater than approximately <NUM> millimeter (mm) and less than or equal to approximately <NUM>, and a center of opening <NUM> may be positioned approximately <NUM> to approximately <NUM> from a bottom end of alignment device <NUM>, i.e., an end opposite the neck portion. In some examples, the center of opening <NUM> may be approximately <NUM> from the bottom end of alignment device <NUM>. In some instances, a diameter of opening <NUM> in proximal first alignment device 401a may be different than a diameter of opening <NUM> in distal first alignment device 401b. The bottom end of first alignment device <NUM> may be attached to the baseboard (not shown) of medical laser system <NUM>, to which Galvo mirror <NUM>, relay mirrors 20a-20d, and other members of laser system <NUM> are secured. For example, proximal and distal first alignment devices 401a, 401b may be attached to the baseboard of medical laser system <NUM> along laser path A, as shown in <FIG>. For example, distal first alignment device 401a may be positioned distally of relay mirrors 20a-20d, and proximal first alignment device 401b may be positioned proximally of relay mirrors 20a-20d, such that both the first and second alignment devices 401a, 401b are positioned along laser path A. An aiming laser beam may be directed into the medical laser system <NUM> along laser path A via, e.g., a connector <NUM> attached to coupling lens assembly <NUM>. As will be described herein, the aiming beam may assist in aligning various elements, including mirrors, of medical laser system <NUM>. Three types of fibers may be used for alignment, based on the type of fiber to which medical laser system <NUM> is to be coupled. For example, the core diameters of the three fibers is approximately <NUM> for a first fiber, approximately <NUM> for a second fiber, and approximately <NUM> for a third fiber. The concentricity of each core is within approximately <NUM>, or within approximately <NUM> of the design. The natural aperture (NA) of each fiber is approximately <NUM>.

<FIG> and <FIG> illustrate a second alignment device <NUM> for assisting in aligning medical laser system <NUM>. Second alignment devices <NUM> may be positioned within each laser cavity <NUM> after the CTH:YAG laser rod is removed (<FIG>). As shown in <FIG>, second alignment devices <NUM> have an L-shaped base with a body portion extending from the base. As will be described herein, two second alignment devices <NUM> (a proximal second alignment device 403a and a distal second alignment device 403b) may be used in an alignment procedure. An opening <NUM> is formed in the body portion of each second alignment device <NUM> and may allow laser light to pass therethrough during an alignment procedure. A diameter of opening <NUM> may equal to or greater than approximately <NUM> and less than or equal to approximately <NUM> and a center of opening <NUM> may be positioned approximately <NUM> to approximately <NUM> from the base of alignment device <NUM>. In some examples, the center of opening <NUM> may be approximately <NUM> from the base of alignment device <NUM>. It will be understood that a diameter of opening <NUM> in proximal second alignment device 403a may be different than a diameter of opening <NUM> in distal second alignment device 403b. The L-shaped configuration of alignment device <NUM> may allow alignment device <NUM> to be positioned and removably fixed on the top surface of laser cavity <NUM> via screws or the like. Distal second alignment device 403b is positioned to be flush against a proximal-most surface of distal end wall 306b. Proximal second alignment device 403a is positioned such that a proximal-most surface of proximal second alignment device 403a is flush with a distalmost surface of proximal sidewall 307b.

<FIG> illustrates a light source <NUM> configured to be used to align medical delivery system <NUM>. Light source <NUM> may include a cable having a distal end <NUM>, the distal end <NUM> may be configured to be connected to fiber ferrule <NUM> of alignment apparatus <NUM> (for example, distal end <NUM> may include a SMA connector). As will be described herein, an aiming light from light source <NUM> may be introduced into medical delivery system <NUM> along light path A to align medical delivery system <NUM>.

<FIG> illustrates an alignment and coupling of a laser guiding beam by medical laser system <NUM> from an aiming laser source <NUM>. Similar to the laser light from cavities 30a-30d, the aiming laser beam is aligned to ensure the aiming laser beam is properly coupled into fiber <NUM>. A fiber (not shown) connecting aiming laser source <NUM> to medical laser system <NUM> may have a diameter of approximately <NUM> and a small divergence. The aiming beam may be a relatively low power light beam in the visual spectrum (approximately <NUM>) that enables an operator to visualize where the output beams from laser cavities 30a-30d may be fired. A portion of aiming light beam may be combined with the output laser by combiner <NUM> and may travel along laser path A. A portion of the aiming laser beam may also pass through combiner <NUM> and travel along a laser path D and may assist in alignment of aiming laser source <NUM>. For example, a pair of first alignment devices 401c, 401d, which may be similar to first alignment device <NUM> shown in <FIG>, including opening <NUM>, may be positioned along laser path D. As described above, opening <NUM> may have a diameter equal to or greater than approximately <NUM> and equal to or less than approximately <NUM>, and a diameter of opening <NUM> in first alignment device 401c may be different from a diameter of first alignment device 401d. As will be described, first alignment devices 401c, 401d may assist in aligning aiming laser source <NUM>.

A method of aligning the medical laser system <NUM> according to an exemplary embodiment will now be described. At the outset, coordinates of various elements of the medical laser system are described herein, reference for which should be made to <FIG>.

A first (e.g., initial) alignment procedure according to an exemplary embodiment will now be described. Connector <NUM> of the aiming laser beam is attached to coupling lens assembly <NUM> (shown in <FIG>) via fiber ferrule <NUM> of coupling lens assembly <NUM>. Alignment devices 401a and 401b are attached to the motherboard of medical laser system <NUM> along laser path A at positions proximal and distal to mirrors 20a-20d, as shown in <FIG>. Coupling lens <NUM> is roughly aligned in the z-direction by moving coupling lens <NUM> in the z-direction such that the aiming laser beam is collimated along laser beam path A. To move coupling lens <NUM> in the z-direction, a user rotates adjusting screw <NUM> (<FIG>) in a clockwise and/or a counterclockwise direction. Clockwise movement of adjusting screw <NUM> may overcome the biasing force of springs <NUM> and cause base frame <NUM> to move in the proximal direction. Counterclockwise movement of adjusting screw <NUM> may allow springs <NUM> to move or bias base frame <NUM> in the distal direction. Iterative rotations of adjusting screw <NUM> in the clockwise and/or counterclockwise direction are performed until the aiming laser beam is collimated along laser path A. The rough alignment of coupling lens <NUM> in the z-direction may be performed visually, and precise alignment of coupling lens <NUM> in the z-direction may be performed at a later step, described herein.

Once coupling lens <NUM> is collimated in the z-direction, adjustment of coupling lens <NUM> in the x- and y-directions is performed. Adjusting screw <NUM> may be rotated clockwise and/or counterclockwise to cause lens holder <NUM> (and coupling lens <NUM>) to move in the x-direction. Adjusting screw <NUM> may also be rotated in clockwise and/or counterclockwise directions to cause stage plate <NUM> (and coupling lens <NUM>) to move in the y-direction. Iterative rotations of adjusting screws <NUM>, <NUM> in clockwise and/or counterclockwise directions is performed until the aiming laser beam passes through openings <NUM> in each of alignment devices 401a, 401b and impinges on a center of Galvo mirror <NUM>. Once the aiming laser beam impinges on the center of Galvo mirror <NUM>, locking screws <NUM> are tightened to secure and maintain a position of stage plate <NUM> and lens holder <NUM>.

Once the aiming laser beam passes through openings <NUM> in each of alignment devices 401a, 401b and impinges on Galvo mirror <NUM>, such that a distalmost face of Galvo mirror <NUM> is perpendicular to laser path A. Galvo mirror <NUM> is subsequently rotated about an x-axis (see <FIG>) such that the aiming laser beam impinging on Galvo mirror <NUM> is reflected proximally along laser path A, i.e., back through openings <NUM> of alignment devices 401a, 401b. Subsequently, minor adjustments may be made in the z-direction via screws <NUM> and springs <NUM> to ensure proper alignment of lens <NUM> in the z-direction. For example, the refractive index between the material of lens <NUM> and the fiber may cause differences in the focal lengths. Yet, once lens <NUM> is aligned in the x- and y-directions, minor modifications based on the difference in focal lengths of the laser may be easily achieved.

The refractive beam indexes through coupling lens <NUM> of the aiming laser beam and the laser generated by laser cavities 30a-30d are different due to the material of coupling lens <NUM> (e.g., a sapphire material). To ensure a proper output by laser fiber <NUM>, optical lens <NUM> may be adjusted such that a spot of light formed by the aiming laser beam may be formed at output coupler windows 32a-32d, e.g., on a material placed adjacent each of output coupler windows 32a-32d that may enable a user to view the light spot. The aiming laser beam may be directed into medical laser system <NUM> as described herein. Coupling lens <NUM> may be moved along the z-direction via screw <NUM> and springs <NUM> until the spot of light is minimized, e.g., a smallest diameter. In other words, for each output coupler window 32a-32d, the position of coupling lens <NUM> may be moved in the z-direction until the diameter of the spot of light on output coupler windows 32a-32d is smallest, and screws <NUM> may be tightened to secure coupling lens <NUM> in the z-direction. In this manner, a position of coupling lens <NUM> in the z-direction may be secured which may optimize an output of the laser energy from the distal end of laser fiber <NUM>.

A second alignment procedure is performed after the aiming laser beam is used to properly position coupling lens <NUM>. The second alignment procedure ensures alignment of each laser cavity 30a-30d. Laser pumping chamber <NUM> in <FIG> is removed from insulating base plate <NUM>, such that each laser cavity <NUM> appears as shown in <FIG>. Second alignment device <NUM> is attached to a first laser cavity (e.g., laser cavity 30a) as shown in <FIG>. As described herein, one of the second alignment devices <NUM> is attached such that its proximal-most surface is flush with the distalmost surface of sidewall 307b. Another of the second alignment device <NUM> is attached such that its distalmost surface is flush against the proximal-most surface of distal end wall 306a. Each of second alignment devices <NUM> are attached via screws or similar fastening devices to a top surface of insulating base plate <NUM> (see <FIG>). The L-shaped configuration of second alignment devices <NUM> ensures openings <NUM> in each of second alignment devices is positioned along laser path C and in a same position as a CTH:YAG laser rod when laser pumping chamber <NUM> is attached to insulating plate <NUM>, shown in <FIG>.

The aiming laser beam is introduced to medical laser system <NUM> by attaching connector <NUM> to fiber ferrule <NUM>, as described above. Elements of medical laser system <NUM> are moved such that the aiming laser beam passes from <NUM> along laser paths A, B, and C, and such that the aiming laser beam passes through opening <NUM> in each of second alignment devices <NUM>. To align the aiming laser beam to pass through openings <NUM>, Galvo mirror <NUM> and first relay mirror 20a are rotated horizontally, e.g. about a y-direction axis, and first relay mirror 20a and first laser cavity 30a are rotated vertically, e.g., about an x-direction axis, as shown in <FIG>. Iterative movements of Galvo mirror <NUM>, first relay mirror 20a, and first laser cavity 30a are performed until the aiming laser beam passes through openings <NUM> in each of second alignment devices <NUM>.

Once the aiming laser beam passes through opening <NUM> in each of second alignment devices <NUM>, reflecting window 36a and output coupler window 32a are adjusted. Reflecting window 36a is adjusted such that the aiming laser beam is reflected from reflecting window 36a and through opening <NUM> in the proximal-most second alignment device <NUM>. Reflecting window 36a is adjusted such that the aiming beam reflected from a surface of window 32a passes through opening <NUM>. This is achieved by rotating reflecting window 36a and output coupler window 32a independently of each other horizontally, e.g. about the y-direction axis, vertically, e.g., about the x-direction axis (<FIG>).

Once the aiming laser beam reflected from reflecting window 36a passes through opening <NUM> in the proximal-most second alignment device <NUM> and the aiming beam is reflected from window 32a through opening <NUM>, the second alignment procedure is performed for all additional laser cavities <NUM> (e.g., laser cavities 30b-30d) of medical laser system <NUM>. In this manner, laser cavities 30a-30d may be properly aligned.

An alignment check may be performed on medical laser system <NUM> after laser cavities 30a-30d are properly aligned. A power meter (not shown) may be attached to the output of coupling lens assembly <NUM> via ferrule <NUM> via a fiber (e.g., a fiber having a diameter of approximately <NUM>). Laser pumping channels <NUM> may be reattached to each of laser cavities 30a-30d (<FIG>), such that an output laser may be generated. Medical laser system <NUM> may be operated to generate the output laser energy at several different example energy levels. For example, medical laser system <NUM> may be operated to generate a low energy output laser, a high energy output laser, and a laser having a large heat dissipation. If the difference in output energy at the power meter for each generated energy level is less than a threshold value (e.g. <NUM>%), the alignment of medical laser system <NUM> is confirmed.

Once alignment of the output laser is confirmed, optimization of the oscillation of the laser from each laser cavity 30a-30d is performed. A fiber having a diameter of approximately <NUM> may be attached via ferrule <NUM>, and a laser may be generated by each laser cavity and delivered through the fiber (e.g., fiber <NUM>) to an energy sensor. Each mirror 36a-36d may be rotated to maximize the output energy of the laser from each laser cavity 30a-30d. Additional fibers having smaller diameters may subsequently attach the power meter via ferrule <NUM> to monitor the change of delivered power or pulse energy from medical laser system <NUM>. For example, fibers having diameters of approximately <NUM> and approximately <NUM> may be attached to medical laser system <NUM> via ferrule <NUM>. The power meter may determine the output power through each of these fibers to ensure the coupling efficiency is with a specific range.

After the optimization of the laser oscillation is complete, an alignment and coupling of a laser guiding beam generated by aiming laser source <NUM> may be performed using the assembly of <FIG>. The laser guiding beam may be an aiming beam or the like, and may be a colored beam (e.g., green, red, or the like) to assist a user to perform a medical procedure using the output laser beam. Aiming laser source <NUM> may be positioned on a mount (not shown) having two-dimensional translation and rotational freedom (e.g., can rotate and translate along the x- and y-axes). Aiming laser source <NUM> generates the aiming laser onto beam combiner <NUM>, such that the aiming laser enters medical laser system <NUM> at an angle approximately perpendicular to laser path A. First alignment devices <NUM>(c) and <NUM>(d) may be positioned along laser path D such that openings <NUM> of each first alignment device <NUM>(c) and <NUM>(d) are positioned along laser path D. A portion of the aiming laser passes through beam combiner. The mount for aiming laser source <NUM> may be rotated and translated in the x- and y-directions until the aiming laser passing through beam combiner <NUM> travels along laser path D and through opening <NUM> in each first alignment device <NUM>(c) and <NUM>(d). Subsequently, connector <NUM> of output laser fiber <NUM> is attached to medical laser system <NUM> via ferrule <NUM> of assembly <NUM>. A distal end of output laser fiber <NUM> is aimed at a target <NUM>. If an image <NUM> (e.g., a light having a color corresponding to the color of the aiming laser beam) is shown on target <NUM>, then the alignment of aiming laser source <NUM> is confirmed and the aiming laser beam is properly coupled to output laser fiber <NUM>. Additional alignment of aiming laser source <NUM> may then be performed to optimize the output shape and brightness of the aiming laser beam from the distal end of output laser fiber <NUM>.

Based on the procedures described herein, elements of medical laser system <NUM> may be properly aligned using an aiming laser beam without the need to generate laser pulses from each laser cavity and delivering the laser pulses to thermal paper. For example, "live" laser pulses generated by the laser cavities may only be necessary for optimizing the resonator oscillation and confirming the beam alignment. Further, the alignment devices provide repeatability and precision to the optomechanical parts and their installation. These devices also provide for improved accuracy over conventional alignment procedures and improve efficiency. Further, the skill required to perform these procedures may be reduced from the skill necessary to perform conventional alignment procedures.

It will be understood that reference is made to a number of cavities and/or mirrors in the medical laser system <NUM>. It will be understood that the devices are not limited to this number and may change according to the requirement of the medical laser system <NUM>. Further, while reference is made to a medical/surgical laser system, the alignment technique described herein is not limited to a medical/surgical laser system and may be used with any laser system.

Claim 1:
A laser system (<NUM>), comprising:
a first laser cavity (30a-30d) configured to output a laser light along a first path (C);
a first mirror (20a-20d) configured to receive the laser light from the first laser cavity (30a-30d), and redirect the laser light along a second path (B) that is different than the first path (C);
a second mirror (<NUM>) configured to receive the laser light from the first mirror (20a-20d), and redirect the laser light along a third path (A) that is different than the first path (C) and the second path (B);
a beam splitter (<NUM>) located at a first position on the third path (A);
a beam combiner (<NUM>) located at a second position on the third path (A); and
a coupling lens assembly (<NUM>) including a lens (<NUM>) located at a third position on the third path (A), wherein the coupling lens assembly (<NUM>) is configured to move the lens in x-, y-, and z-directions.