System method and apparatus for selecting and controlling light source bandwidth

Abstract

The bandwidth selection mechanism includes a first actuator mounted on a second face of a dispersive optical element, the second face being opposite from a reflective face, the first actuator having a first end coupled to a first end block and a second end coupled to a second end block, the first actuator being operative to apply equal and opposite forces to the first end block and the second end block to bend the body of the dispersive optical element along the longitudinal axis of the body and in a first direction normal to the reflective face of the dispersive optical element. The bandwidth selection mechanism also includes a second actuator being operative to apply equal and opposite forces to bend the body along the longitudinal axis of the body, in a second direction perpendicular to the reflective face of the dispersive optical element.

What is claimed is: 
     
       1. A bandwidth selection mechanism comprising:
 a dispersive optical element having a body including a reflective face of dispersion including an area of incidence extending in a longitudinal axis direction along the reflective face of the dispersive optical element; 
 a first end block, disposed at a first longitudinal end of the body; 
 a second end block, disposed at a second longitudinal end of the body, the second longitudinal end being opposite the first longitudinal end; 
 a first actuator mounted on a second face of the dispersive optical element, the second face being opposite from the reflective face, the first actuator having a first end coupled to the first end block and a second end coupled to the second end block, the first actuator being operative to apply equal and opposite forces to the first end block and the second end block to bend the body along the longitudinal axis of the body and in a first direction normal perpendicular to the reflective face of the dispersive optical element; and 
 a second actuator mounted on a third face of the dispersive optical element, the third face being normal perpendicular to the reflective face, the second actuator having a first end coupled to the first end block with a first flexture and a second end coupled to the second end block with a second flexture, the first actuator being operative to apply equal and opposite forces to the first end block and the second end block to bend the body along the longitudinal axis of the body, in a second direction perpendicular to the reflective face of the dispersive optical element, the second direction also being perpendicular to the first direction the second actuator including a pressurized fluid force application mechanism. 
 
     
     
       2. The bandwidth selection mechanism of  claim 1 , wherein the pressurized fluid force application mechanism is a pneumatic mechanism. 
     
     
       3. The bandwidth selection mechanism of  claim 1 , wherein the pressurized fluid force application mechanism is a hydraulic mechanism. 
     
     
       4. The bandwidth selection mechanism of  claim 1 , wherein the pressurized fluid force application mechanism is variable. 
     
     
       5. The bandwidth selection mechanism of  claim 1 , further comprising:
 a manual preload adjustment at constant, fixed deflection on at least one of the first actuator and the second actuator. 
 
     
     
       6. The bandwidth selection mechanism of  claim 5 , further comprising a feedback control loop on the second actuator in response to a spectral parameter of the light. 
     
     
       7. The bandwidth selection mechanism of  claim 1 , further comprising a pneumatic actuation and feedback control loop on at least one of the first actuator and the second actuator, in response to spectral parameters of the light. 
     
     
       8. The bandwidth selection mechanism of  claim 1 , further comprising a variable aperture positioned between the incident beam and the reflective face of the dispersive optical element. 
     
     
       9. The bandwidth selection mechanism of  claim 8 , wherein the variable aperture has a variable dimension along a direction of bending of the second actuator. 
     
     
       10. The bandwidth selection mechanism of  claim 1 , further comprising a light beam expander for expanding an incident a light beam across the area of incidence. 
     
     
       11. A method of selecting bandwidth comprising:
 expanding an incident light beam across an area of incidence of a reflective surface of a dispersive optical element; 
 bending the reflective surface of the dispersive optical element with a first bending force applied by a first actuator in a first direction normal perpendicular to the reflective face of the dispersive optical element; 
 bending the reflective surface of the dispersive optical element with a second bending force applied by a second actuator in a second direction perpendicular to the reflective face of the dispersive optical element, the second direction also being perpendicular to the first direction; and 
 decoupling the second bending force through at least one flexture so that decoupled second force does not increase or decrease the first force. 
 
     
     
       12. The method of  claim 11 , wherein in bending the reflective surface of the dispersive optical element in the first direction uniformly varies a spacing between dispersive features on the reflective surface as a function of position in the first direction. 
     
     
       13. The method of  claim 11  further comprising:
 modifying a dimension of the incident light beam upon the reflective surface to encompass different regions of the bent reflective surface. 
 
     
     
       14. The method of  claim 11 , wherein the reflective surface is bent in alt at least one of the first direction and the second direction in response to feedback from a property of the reflected light beam. 
     
     
       15. A bandwidth selection mechanism comprising:
 a dispersive optical element having a body including a reflective face of dispersion including an area of incidence extending in a longitudinal axis direction along the reflective face of the dispersive optical element;   a first end block, disposed at a first longitudinal end of the body;   a second end block, disposed at a second longitudinal end of the body, the second longitudinal end being opposite the first longitudinal end;   a first force device having a first end coupled to the first end block and a second end coupled to the second end block, the first force device being operative to apply a first force to the first end block and apply a second force the second end block to bend the body along the longitudinal axis of the body and in a first direction perpendicular to the reflective face of the dispersive optical element, the first force and the second force being equal and opposite; and   a second force device having a first end coupled to the first end block and a second end coupled to the second end block, the second force device being operative to apply a third force to the first end block and apply a fourth force to the second end block to bend the body along the longitudinal axis of the body, in a second direction perpendicular to the first direction, the third force and the fourth force being equal and opposite.   
     
     
       16. The bandwidth selection mechanism of claim 15, wherein at least one of the first force device and the second force device includes at least one of a piezoelectric actuator, an electromechanical actuator, a motor, a stepper motor, electromagnetic actuator, magnetostrictive actuator or a pressurized fluid force application mechanism and wherein the pressurized fluid force application mechanism includes at least one of a pneumatic mechanism or a hydraulic mechanism. 
     
     
       17. The bandwidth selection mechanism of claim 16, wherein the pressurized fluid force application mechanism is variable. 
     
     
       18. The bandwidth selection mechanism of claim 15, further comprising:
 a manual preload adjustment at constant, fixed deflection on at least one of the first force device and the second force device.   
     
     
       19. The bandwidth selection mechanism of claim 18, further comprising a feedback control loop on the second force device in response to at least one parameters of the light. 
     
     
       20. The bandwidth selection mechanism of claim 16, further comprising a pressurized fluid force and feedback control loop on at least one of the first force device and the second force device, in response to at least one parameter of the light. 
     
     
       21. The bandwidth selection mechanism of claim 15, further comprising a variable aperture positioned between the incident beam and the reflective face of the dispersive optical element. 
     
     
       22. The bandwidth selection mechanism of claim 21, wherein the variable aperture has a variable dimension along a direction of bending of the second actuator. 
     
     
       23. The bandwidth selection mechanism of claim 15, further comprising a light beam expander for expanding an incident a light beam across the area of incidence. 
     
     
       24. The bandwidth selection mechanism of claim 15, wherein the first force device is mounted adjacent to a second face of the dispersive optical element, the second face being opposite from the reflective face. 
     
     
       25. The bandwidth selection mechanism of claim 15, wherein the second force device is mounted adjacent to a third face of the dispersive optical element, the third face being perpendicular to the second face. 
     
     
       26. The bandwidth selection mechanism of claim 15, wherein the first end of the second force device is coupled to the first end block through a first flexture and the second end of the second force device is coupled to the second end block through a second flexture, the first flexture and the second flexture decouple the second force and the first force. 
     
     
       27. The bandwidth selection mechanism of claim 15, wherein the second direction is perpendicular to the reflective face of the dispersive optical element. 
     
     
       28. A method of selecting bandwidth comprising:
 expanding an incident light beam across an area of incidence of a reflective surface of a dispersive optical element;   bending the reflective surface of the dispersive optical element with a first bending force applied by a first force device in a first direction perpendicular to the reflective face of the dispersive optical element; and   bending the reflective surface of the dispersive optical element with a second bending force applied by a second force device in a second direction perpendicular to the first direction.   
     
     
       29. The method of claim 28, wherein in bending the reflective surface of the dispersive optical element in the first direction uniformly varies a spacing between dispersive features on the reflective surface as a function of position in the first direction. 
     
     
       30. The method of claim 28, further comprising:
 modifying a dimension of the incident light beam upon the reflective surface to encompass different regions of the bent reflective surface.   
     
     
       31. The method of claim 28, wherein the reflective surface is bent in at least one of the first direction and the second direction in response to feedback from at least one parameter of the reflected light beam. 
     
     
       32. The method of claim 28, further comprising decoupling the second bending force through at least one flexture so that the decoupled second force does not increase or decrease the first force. 
     
     
       33. The method of claim 28, wherein the second direction is perpendicular to the reflective face of the dispersive optical element.