Patent Publication Number: US-2023149983-A1

Title: Structural-coupling system for laser and method of use

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority in U.S. Provisional Patent Application No. 63/278,901 Filed Nov. 12, 2021, which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a laser coupling system and method for use thereof, and more specifically to a laser coupling system for connecting a fiber laser or fiber delivered laser at a remote interface or bulk head interface for protecting or isolating the laser generator from the laser optical output. Common applications of the invention will be within a power facility during shut down periods for maintenance and cleaning. 
     2. Description of the Related Art 
     Laser cleaning via ablation is often used to clean and remove coatings from the surfaces of chemical plants, petrochemical plants, power facilities, nuclear facilities, and other industrial plants and facilities. Laser ablation is becoming a more common maintenance decoating process necessary to maintain proper functions of such facilities. However, in some situations, radiation or other risks could damage laser equipment, necessitating expensive and tedious shielding for the laser equipment. What is needed is a system which allows the laser optic to be used within a contaminated or otherwise dangerous location while retaining the delicate components of the laser system in an exterior, safe location. Sometimes the dividing line between contaminated or hazardous area is an open ingress/egress which must be cleared and removed of blockage in an emergency situation. A method to allow for fiber and optic coupling at the ingress/egress and/or through a barrier and provide quick isolation of the optical elements is essential. 
     Heretofore there has not been available a system or method for a laser system with the advantages and features of the present invention. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention generally provides a structural coupling for use within a laser system. In a preferred embodiment, a laser system for cleaning purposes would be displaced within a facility having dangerous conditions which could potentially damage the components of the laser, such as within a nuclear power facility. In such an environment, protecting the laser components typically requires shielding which can fail, resulting in potential contamination of laser generator and components. In the preferred embodiment, the structural coupling would allow the laser to pass through a structural element, such as a wall, or at a passthrough location such as an ingress or egress location to be used on the interior of the facility such that the end effector may be freely used within the facility while the mobile laser unit itself is safely stored outside of the dangerous area. The coupling allows the laser to pass through the structural element or opening to the end effector without exposing the laser itself to potential contamination. 
     In the preferred embodiment, a quick connect fiber or a “fiber to fiber” coupling allows for laser beam delivery in an area of high contamination or nuclear exposure while keeping the laser system and controls external to the restricted area. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings constitute a part of this specification and include exemplary embodiments of the present invention illustrating various objects and features thereof. 
         FIG.  1    is a diagrammatic plan view of a typical environment where an embodiment of the present invention may be deployed, identifying areas of danger or concern. 
         FIG.  2    is an elevational drawing showing an embodiment of the present invention. 
         FIG.  3    is a three-dimensional view thereof. 
         FIG.  4    is a sectional view about a connector element thereof. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     I. Introduction and Environment 
     As required, detailed aspects of the present invention are disclosed herein, however, it is to be understood that the disclosed aspects are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art how to variously employ the present invention in virtually any appropriately detailed structure. 
     Certain terminology will be used in the following description for convenience in reference only and will not be limiting. For example, up, down, front, back, right and left refer to the invention as orientated in the view being referred to. The words, “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the aspect being described and designated parts thereof. Forwardly and rearwardly are generally in reference to the direction of travel, if appropriate. Said terminology will include the words specifically mentioned, derivatives thereof and words of similar meaning. 
     II. Preferred Embodiment Structural Coupling Laser System  2   
       FIG.  1    shows how zones within a facility  4 , such as a nuclear power facility, may include several different ranges of danger or potential contamination. A primary purpose of the present invention is to allow the use of a laser system for cleaning one of the interior zones while retaining the delicate elements of the laser on the exterior of the dangerous or hazardous area. 
     As shown, the environment is divided into three zones. Zone One 10 is a clean zone. All zones from here on out to the exterior would be “clean” from hazardous radiation or other dangers that are present in the other zones. The laser  20  is shown to reside in this area but can also be placed in Zone Two 8 depending on the level of radiological contamination. A high power fiber cable  22  can connect the laser  20  via structural coupling  24  featuring a fiber-to-fiber interface is stubbed between the barrier  12  between Zone Two 8 and Zone Three 6. 
     Zone Two 8 is a restricted contaminated area. A door  18  or designated ingress/egress location within the barrier  16  may provide access to this zone. The laser  20  can be in this zone depending on company policies and procedures. Typically, anything that moves air in or out of a system needs to be filtered and has a higher risk of contamination. If a water chiller or air filter unit  30  is stored in this zone it may become contaminated. If the water chiller or air filter unit is integrated with the laser system, the entire laser may be lost to this zone. An external water chiller and separated air filter unit could be installed in this area and laser changed to a water-water system which would allow for the chiller to remain in Zone Two while minimizing chances of the laser needing to be retained within this zone due to contamination. 
     Zone Three 6 is a radiologically controlled area. A door or designated ingress/egress location  14  within the barrier  12  may provide access to this zone. In a nuclear power facility environment, there are loose alpha particles in this zone. Everything taken into this zone must be protected or sealed. Items taken into this zone may be lost to this zone and must be left behind if contaminated. Smaller water chiller units and local fume extraction systems can be brought into Zone Three but will likely need to be kept in this area until final disposal. 
       FIG.  2    shows how a structural coupling  24  can bridge a wall  12 ,  16  or other structural element to allow for use of the laser system  20  on the interior of the structure while safely storing the delicate elements of the laser system on the safe, exterior. Here it is shown how a structural separation barrier  12 , such as a wall, can separate a laser  20  from the optic  26  (also referred to as an end effector) via a pair of fibers  22  connected at a coupling  24  which passes through the structural separation barrier  12  and which can directly connect to the fibers on either side. This allows the laser components  20  to be retained within the safer zone (e.g. Zone One 10 or Zone Two 8) while the optical end  26  is deployed in the dangerous zone (e.g. Zone Three 6). 
       FIG.  3    shows how the laser  20  and coupling  24  would be integrated in a real-world environment. The facility  4  has a wall  12  which is penetrated by the coupling  24 . The optical connectors  28  allow for the laser  20  to send its beam through the wall  12  via the coupling  24  and be usable via the optic  26 . 
       FIG.  4    shows a sectional view of the coupling  24  passing through the wall  12  between the safer zone, Zone Two 8, and the contaminated zone, Zone Three 6. The first end of the coupling  24  connects to a fiber  22  connecting back to the laser  20  via a first optical connector  28  which has a collimation lens  40  within the connector. A protection window  38  is disposed between the collimation lens  40  and the threaded connector  36  which threads onto a corresponding threaded receiver  34  of the coupling  24 . The optical channel through a structure will be protected by means of a protection window  38  on each end as well. Other connection means may be suitable. 
     Similarly, a separate fiber  22  connects to the optic  26  which includes its own identical connector  28  and which houses a focus lens set  42  between the fiber and another protection window  38 . The collimation lens and the focus lens set allow the connector  24  to seamlessly transfer the laser  32  through the coupling  24 . 
     While the examples provided above show one application of the present invention, other enclosures (e.g. submarines) may include similar needs for separating a laser source from an optic for laser ablation or other purposes. The structural connector would be usable through any barrier of any thickness and would protect the laser source from contamination or other undesirable effects that may otherwise result from being placed in the same enclosure as the optic. 
     It is to be understood that while certain embodiments and/or aspects of the invention have been shown and described, the invention is not limited thereto and encompasses various other embodiments and aspects.