Buckling mode actuation of fiber scanner to increase field of view
Described herein are embodiments of fiber scanning systems and methods of scanning optical fibers. The disclosed systems and methods advantageously provide an improvement to the scanning range, the oscillation amplitude, and/or the maximum pointing angle for an optical fiber in a fiber scanning system by inducing a buckling of a portion of the optical fiber.
1. A system comprising:
an optical fiber having a distal fiber end and a proximal fiber end;
an electromechanical transducer mechanically coupled to the optical fiber between the distal fiber end and the proximal fiber end; and
a voltage source in electrical communication with the electromechanical transducer, the voltage source configured to apply a plurality of voltages to the electromechanical transducer to vary an orientation of the distal fiber end of the optical fiber according to a spiral path, wherein the plurality of voltages includes a first voltage having a sinusoidal profile with an amplitude that increases or decreases as a function of time, and a second voltage that periodically ramps in magnitude.
2. The system of claim 1 , wherein the distal fiber end is unconstrained.
3. The system of claim 1 , wherein increasing or decreasing of the amplitude of the first voltage and ramping of the magnitude of the second voltage are synchronized with respect to one another.
4. The system of claim 1 , wherein a frequency associated with increasing or decreasing the amplitude of the first voltage is about equal to a repetition frequency of the second voltage.
5. The system of claim 1 , wherein a sinusoidal frequency of the first voltage is greater than a repetition frequency of the second voltage.
6. The system of claim 1 , wherein application of the second voltage by the voltage source results in a change in overall length of the electromechanical transducer between a distal end of the electromechanical transducer and a proximal end of the electromechanical transducer.
7. The system of claim 1 , wherein the electromechanical transducer is mechanically coupled to the optical fiber by a first joint at a distal end of the electromechanical transducer and by second joint at a proximal end of the electromechanical transducer.
8. The system of claim 7 , wherein application of the second voltage by the voltage source buckles the optical fiber between the first joint and the second joint.
9. The system of claim 7 , wherein application of the second voltage by the voltage source increases a pointing angle of the distal fiber end of the optical fiber beyond that of the distal fiber end of the optical fiber in an absence of the second voltage.
10. The system of claim 1 , wherein the electromechanical transducer comprises a piezo tube and wherein the optical fiber passes through the piezo tube along a longitudinal axis of the piezo tube.
11. The system of claim 1 , wherein the plurality of voltages are superimposed on one another.
12. The system of claim 1 , wherein the electromechanical transducer comprises a first electromechanical transducer and a second electromechanical transducer, wherein the first electromechanical transducer is mechanically coupled to the optical fiber by a first joint, wherein the second electromechanical transducer is mechanically coupled to the optical fiber by a second joint, wherein the first joint is positioned between the second joint and the distal fiber end, and wherein the second joint is positioned between the first joint and the proximal fiber end.
13. The system of claim 12 , wherein application of the second voltage by the voltage source buckles the optical fiber between the first joint and the second joint.
14. The system of claim 12 , wherein the first electromechanical transducer includes a hub, a frame surrounding the hub, and a plurality of lateral electromechanical transducers mechanically coupled to the frame and to the hub, wherein the optical fiber passes through the hub, and wherein the hub is mechanically coupled to the optical fiber by the first joint.
15. The system of claim 12 , wherein the first electromechanical transducer comprises a first piezo tube, wherein the first joint is positioned at a distal end of the first piezo tube, wherein the second electromechanical transducer comprises a second piezo tube, wherein the second joint is positioned at a distal end of the second piezo tube, and wherein the optical fiber passes through the first piezo tube and the second piezo tube along longitudinal axes of the first piezo tube and the second piezo tube.
16. The system of claim 15 , further comprising a support tube, wherein the second piezo tube is positioned within the support tube, wherein a distal end of the support tube is mechanically coupled to a proximal end of the first piezo tube, and wherein a proximal end of the support tube is mechanically coupled to a proximal end of the second piezo tube.
17. The system of claim 1 , wherein the proximal fiber end is coupled to an optical source for transmitting electromagnetic radiation generated by the optical source through the optical fiber from the proximal fiber end to the distal fiber end.
18. A method comprising:
applying a plurality of voltages to an electromechanical transducer of an optical fiber scanning system to vary an orientation of a distal fiber end of an optical fiber according to a spiral path, wherein the optical fiber scanning system includes:
the optical fiber, wherein the optical fiber has the distal fiber end and a proximal fiber end;
the electromechanical transducer, wherein the electromechanical transducer is mechanically coupled to the optical fiber between the distal fiber end and the proximal fiber end; and
a voltage source in electrical communication with the electromechanical transducer for applying the plurality of voltages;
wherein the plurality of voltages includes a first voltage having a sinusoidal profile with an amplitude that increases or decreases as a function of time, and a second voltage that periodically ramps in magnitude.
19. The method of claim 18 , wherein the electromechanical transducer is mechanically coupled to the optical fiber by a first joint at a distal end of the electromechanical transducer and by second joint at a proximal end of the electromechanical transducer.
20. The method of claim 18 , wherein the electromechanical transducer comprises a first electromechanical transducer and a second electromechanical transducer, wherein the first electromechanical transducer is mechanically coupled to the optical fiber by a first joint, wherein the second electromechanical transducer is mechanically coupled to the optical fiber by a second joint, wherein the first joint is positioned between the second joint and the distal fiber end, and wherein the second joint is positioned between the first joint and the proximal fiber end.