Nonlinear adaptive control of optical jitter with a new liquid crystal beam steering device

This paper presents a new approach to active control of optical jitter with a new transmissive liquid crystal beam steering device, or tilt corrector. The device is driven by a linear time-invariant feedback control loop and an adaptive control loop to maximize the jitter-rejection bandwidth. In contrast to conventional fast steering mirrors, the liquid crystal device optically redirects the laser beam. The new device has no moving parts and requires low operating power. The paper presents experimental results that demonstrate the capabilities of the liquid crystal device and the adaptive controller to suppress high-bandwidth jitter. For the control system, the liquid crystal device presents nonlinearities due to a rate limit and quantization. The experimental results show the importance of modeling the nonlinearities in the adaptive controller.

[1]  Tsu-Chin Tsao,et al.  Optimal Suppression of Laser Beam Jitter by High-Order RLS Adaptive Control , 2008, IEEE Transactions on Control Systems Technology.

[2]  Bernard Widrow.  Adaptive inverse control , 1990, Defense, Security, and Sensing.

[3]  Tsu-Chin Tsao,et al.  Adaptive control of jitter in a laser beam pointing system , 2006, 2006 American Control Conference.

[4]  Steve Gibson,et al.  Adaptive suppression of optical jitter with a new liquid crystal beam steering device , 2007, SPIE Defense + Commercial Sensing.

[5]  B L Ellerbroek,et al.  Adaptive optics: wave-front correction by use of adaptive filtering and control. , 2000, Applied optics.

[6]  Tsu-Chin Tsao,et al.  Adaptive control of a MEMS steering mirror for suppression of laser beam jitter , 2005, Proceedings of the 2005, American Control Conference, 2005..

[7]  Tsu-Chin Tsao,et al.  Adaptive control of a tilt mirror for laser beam steering , 2004, Proceedings of the 2004 American Control Conference.

[8]  Roberto Ragazzoni,et al.  Kalman-filter-based optimal control law for star-oriented and layer-oriented multiconjugate adaptive optics , 2004, SPIE Astronomical Telescopes + Instrumentation.

[9]  Daniel G. Cole,et al.  Adaptive feedback control of optical jitter using Q-parameterization , 2004 .

[10]  C.-C. Chang,et al.  Adaptive optics with a new modal decomposition of actuator and sensor spaces , 2001, Proceedings of the 2001 American Control Conference. (Cat. No.01CH37148).

[11]  Tsu-Chin Tsao,et al.  Variable-order adaptive control of a microelectromechanical steering mirror for suppression of laser beam jitter , 2006 .

[12]  S. Gibson,et al.  Adaptive filtering and control for wavefront reconstruction and jitter control in adaptive optics , 2005, Proceedings of the 2005, American Control Conference, 2005..

[13]  Eric H. Anderson,et al.  Active suppression of acoustically induced jitter for the airborne laser , 2000, Defense, Security, and Sensing.

[14]  Tsu-Chin Tsao,et al.  Optimal Jitter Rejection In Laser Beam Steering with Variable-Order Adaptive Control , 2006, Proceedings of the 45th IEEE Conference on Decision and Control.

[15]  Dong-Feng Gu,et al.  Dual frequency liquid crystal devices for infrared electro-optical applications , 2002, SPIE Optics + Photonics.

[16]  Victor A. Skormin,et al.  Adaptive jitter rejection technique applicable to airborne laser communication systems , 1995 .

[17]  Bruce Winker,et al.  Compact 4 cm aperture transmissive liquid crystal optical phased array for free-space optical communications , 2005, SPIE Optics + Photonics.

[18]  S. Gibson,et al.  Adaptive optics with adaptive filtering and control , 2004, Proceedings of the 2004 American Control Conference.

[19]  Bernard Widrow,et al.  Adaptive Signal Processing , 1985 .

[20]  Brij N. Agrawal,et al.  Jitter Control of Space and Airborne Laser Beams , 2004 .

[21]  Steve Gibson,et al.  Adaptive Control of MEMS Mirrors for Beam Steering , 2004 .

[22]  Tsu-Chin Tsao,et al.  Adaptive control of a MEMS steering mirror for free-space laser communications , 2005, SPIE Optics + Photonics.

[23]  Allan Wirth,et al.  Wavefront control with a spatial light modulator containing dual-frequency liquid crystal , 2004, SPIE Optics + Photonics.

[24]  Shyh-Biau Jiang,et al.  An unwindowed multichannel lattice filter with orthogonal channels , 1995, IEEE Trans. Signal Process..