Abstract:
An optical system is formed of a plurality of optical sources and components of different laser-based equipment systems. The sources and/or components may be combined and/or eliminated to reduce complexity, cost and/or overall weight of the system by consolidating multiple laser sources into a reduced number of sources, and by multiplexing different wavelength signals over common carriers. A laser engagement system and an infrared aim light (or infrared illuminator) are powered by a single laser source which is adopted for use with conventional equipment by lengthening the duration of the coded pulses emitted by the transmitter. The transmitter may be triggered in response to the heat and/or pressure generated by the blank upon firing. A visible bore light may be eliminated by connecting infrared and/or visible aim light directly to a rifle barrel.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to optics and optical systems and devices. The present invention also relates to a method of operating a multi-functional optical system. 
     BACKGROUND OF THE INVENTION 
     Multi-function laser-based systems are employed for a variety of purposes. For example, it has been suggested to provide up to seven different laser-based equipment systems in combination, including the following: (1) a laser range finder; (2) an infrared aim light; (3) an infrared illuminator (a flashlight); (4) a visible aim light; (5) a visible bore light (a mandrel boresight laser for aligning sights); (6) a combat identification system; and (7) a multiple integrated laser engagement system for laser-tag simulated exercises, referred to herein as a “laser simulation system.” 
     Prior art multi-function laser-based systems are generally complex and bulky. There is a need in the art for a system in which components are combined and/or eliminated to reduce complexity, cost and overall weight. In particular, there is a need for an optical system which provides multiple functions with a reduced number of optical sources and/or other components. Additionally, there is a need for an uncomplicated method of operating a multi-function optical system. 
     SUMMARY OF THE INVENTION 
     The disadvantages of the prior art are overcome to a great extent by the present invention. Although the invention is illustrated in the drawings in connection with known functions, the invention is considered applicable to a number of other uses as well. In general, the invention may be applicable wherever complexity, cost and/or weight can be reduced by combining the functionality of optical sources and/or other components. 
     According to one aspect of the invention, a plurality of optical sources and components of different laser-based equipment systems are combined and/or eliminated to reduce complexity, cost and/or overall weight. This aspect may be accomplished by consolidating multiple laser sources into a reduced number of sources, and by multiplexing different wavelength signals over common carriers, and there are other aspects of the invention. 
     According to another aspect of the invention, a laser simulation system and an infrared aim light (or infrared illuminator) are powered by a single laser source. According to this aspect of the invention, a single laser source can be adopted for the laser simulation system by lengthening the duration of the coded pulses emitted by the laser simulation system transmitter. The shorter wavelength pulses are attenuated to a greater degree by the filter cap on the laser simulation system receiver. Thus, by lengthening the pulses, the laser simulation system receiver is actuated by the pulses in the same way as if they were conventional pulses. The laser simulation system receiver may optionally be located on the person who is being targeted. 
     According to another aspect of the invention, the laser simulation system transmitter is triggered in response to the heat and/or pressure generated by blank ammunition gasses upon firing. This provides a way to ensure that the transmitter is only initiated when someone actually pulls the trigger on the laser simulation system. 
     According to another aspect of the invention, the visible bore light (item (5) mentioned above) may be eliminated by connecting the infrared and/or visible aim light directly to the rifle barrel. 
     According to another aspect of the invention, a multifunction lens systems is provided which integrates multiple lenses for outputting several different functions. The lens system may be formed of first and second lenses fixedly connected to each other, or one formed on a portion of the other, with each lens providing various functional outputs. Optionally, the first lens can be a collimating lens. 
     According to yet another aspect of the invention, a method of fabricating an optical system comprised of a plurality of optical sources and components of different laser-based equipment systems is provided. Laser sources operated at different wavelengths are wavelength division multiplexed (WDM) through various optical transmission lines to power six or more different functional outputs. 
    
    
     These and other advantages and features of the invention will become apparent from the following detailed description of the invention which is provided in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of an optical system constructed in accordance with a preferred embodiment of the invention. 
     FIG. 2 is a cross sectional view of a lens device constructed in accordance with a preferred embodiment of the invention. 
     FIG. 3 is a partial schematic view of another optical system constructed in accordance with another preferred embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring now to the drawings, where like reference numerals designate like elements, there is shown in FIG. 1 an optical system  1  constructed in accordance with a preferred embodiment of the invention. The illustrated system  1  has a first source  10  for generating a first input laser energy  5 . The first input energy  5  may have a wavelength in the near infrared spectrum (the infrared spectrum near the visible spectrum), for example from about 820 nanometers (nm) to about 860 nm, preferably about 825 nm. 
     The first input energy  5  propagates through an optical transmission line  40  and is launched into an optical coupler or splitter  16 . The coupler  16  distributes optical power among two or more ports  17 ,  19 . The coupler  16  directs a first portion of the input energy  5  into transmission line  48  and a second portion of the input energy  5  into transmission line  46  (in direction  56 ). The split of the first portion and the second portion will depend upon the requirements of the system. For example the split may be 60% to 40%, 80% to 20%, 100% to 0%, or other split. The input energy  5  propagating in transmission line  48  enters a lens  20  and is output from the lens  20  as an infrared illuminating light  26 . 
     The input energy  5  propagating through transmission line  46  enters a multiplexer  18 . The input energy  5  is transmitted through the multiplexer  18  and is launched into transmission line  50  (in direction  59 ) to enter a second lens  24 . Light energy  5  output from the second lens  24  may be used in a laser training simulation system. A conventional laser simulation system source operates at 904 nanometers. Thus, according to the illustrated embodiment, the 825 to 860 nanometers source  10  is adopted for the laser simulation system by lengthening the duration of the coded pulses  30 . The shorter wavelength pulses (825 nm to 860 nm, which are shorter than the conventional 904 nm) are attenuated to a greater degree by the filter cap (not shown) on the known laser simulation system receiver (not shown). Thus, the laser simulation system receiver is actuated by the 825 to 860 nm pulses in the same way as if they were 904 nm pulses. The laser simulation system receiver may be located on the person (not shown) who is targeted by the laser simulation system transmitter  24 . 
     In a known laser simulation system, the user pulls a trigger to fire a blank cartridge to simulate the firing of an actual round and, in response, a sensor on the laser simulation system transmitter triggers the laser. The player identification and transmitter type can be encoded on the laser beam using a laser simulation system code. An electronic controller is connected through an amplifier to the optical detectors to decode the output signals thereof and provide an indication that the person carrying the receiver has been hit by the laser. 
     It is possible, however, for a user to simulate the firing of a blank cartridge without actually firing a blank by manipulating the rifle to “re-coil” such that the laser simulation system transmitter is operated. Thus, the laser shot from that transmitter can go unrecognized, giving the user an unfair advantage. To overcome these problems, the present invention provides a laser simulation system transmitter  10 ,  24 ,  30  that is trigger in response to the heat and/or pressure generated by the blank ammunition gasses upon firing. This provides a way to ensure that the transmitter  10 ,  24 ,  30  is only initiated when the user actually pulls the trigger (not shown). 
     Further, the optical system  1  has a second driver or source  12  for providing a second input energy  7 . The second input energy  78  may be laser light with a wavelength in the visible spectrum (e.g., about 630 nm to about 650 nm, preferably about 635 nm). The second input energy  7  propagates through optical transmission line  42  into the coupler  16 . The coupler  16  directs about 100% of the input energy  7  into transmission line  46  in direction  54 . The input energy  7  propagating through transmission line  46  enters the multiplexer  18 . The multiplexer  18  directs the input energy  7  into transmission line  50  in direction  59  to enter the second lens  24 . The input energy  7  output from the second lens  24  may be used as a visible aiming light  32 . 
     In addition, a third driver or source  14  may be used to provide a third input energy  9  having a wavelength of about 1530 nm to about 1555 nm, preferably about 1538 nm. In a preferred embodiment, the third input energy  9  is amplified by an erbium-doped fiber amplifier  70  for further propagation in transmission line  44   
     The third input energy  9  traveling along optical transmission line  44  enters circulator  62  which acts as a passive waveguide junction between the multiplexer  18  and a photodetector  64 . The third input energy  9  transmitted out of the circulator  62  in direction  65  enters the multiplexer  18 . The multiplexer  18  inputs the third input energy  9  into transmission line  50  in direction  59 . Thus, the input energy  9  exits the second lens  24  as fifth output light  34 , which may be used, for example as a combat identification transmission. 
     Additionally, the input energy  9  exiting the lens  24  may form a light  36  for a laser rangefinder system. According to this aspect of the invention, the output light  36  is returned back to the lens  24  as returned light  38 , which may be used to determine target position, target coordinates and the like. The returned light  38  is propagated back through optical communication line  50  in direction  66  to the multiplexer  18  and from there through the circulator  62  and into a photodetector  64 . The photodetector  64  may be a processor-based system which can receive the returned light  38  and integrate and process the information contained therein. 
     If desired, the optical system  1  also may be provided with visible borelight assembly  3 . In the borelight assembly  3 , input energy  7  travels in direction  58  along optical transmission line  52 . A connector  60  is included in the transmission line  52 . The input energy  7  enter an additional lens  22  and exits as optional output light  29 . In an alternative embodiment of the invention, the entire borelight assembly  3  may be eliminated by connecting the output light  30  (infrared aim light) and/or the fourth output light  32  (visible aim light) directly to the rifle barrel. 
     FIG. 2 shows a lens device  2  constructed in accordance with a preferred embodiment of the invention. Lens device  2  comprises the first lens  20  and the second lens  24  fixedly connected to each other. The first input energy  5  enters the first lens  20  and exits as an output light  26 . As discussed above, the output light  26  may be used for infrared illumination. 
     Additionally, first input energy  5  can enter second lens  24  and exit as third output light  30 , to be used in an otherwise conventional laser simulation system. The second input energy  7  enters second lens  24  and exits as fourth output light  32 . The fourth output light may be used as a visible aiming light. The third input energy  9  enters second lens  24  and exits as fifth output light  34  or sixth output light  36 . Preferably, the fifth output light  34  is used for combat identification transmission and the sixth output light  36  is used in a rangefinder system. 
     Thus, the optical system  1  has multiple functions and integrates multiple lenses for outputting light beams or several different purposes. The lens system can optionally comprise a first lens and a second lens fixedly connected to each other, with each lens providing various functional outputs. 
     Referring now to FIG. 3, there is shown an alternative optical power supply system in which the first input energy  5  propagates through an optical transmission line  40  and is launched into an optical splitter  200 . The splitter  200  distributes the signal  5  into two or more ports  202 ,  204 . 40% of the power  5  may be propagated into an optical transmission line  48 . 60% of the power is distributed into a second line  208 . The percentages of the power distributed through the two lines  48 ,  208  may be changed as desired. The signal  7  from the second source  12  is transmitted through optical line  42  and is coupled with the power in the line  208  by a coupler  206 . The coupler  206  outputs a desired portion of the two signals  5 ,  7  into an output line  46 . The output line  46  is connected to the multiplexer  18  as discussed above. 
     Reference has been made to preferred embodiments in describing the invention. However, additions, deletions, substitutions, or other modifications which would fall within the scope of the invention defined in the claims may be implemented by those skilled in the art without departing from the spirit or scope of the invention. Accordingly, the invention is not to be considered as limited by the foregoing description, but is only limited by the scope of the appended claims.