Optical limiters using photorefractive nonlinearities

Optical limiters using photorefractive nonlinearities

The ability of photorefractive crystals such as barium titanate and strontium barium niobate to record spatially phase shifted real time holograms with high diffraction efficiency is the basis of many new optical devices involving coherent amplification. Some examples are unidirectional ring resonators, passive phase conjugate mirrors and coherent image amplifiers. 1 While in the past, most att...

Self-protecting semiconductor optical limiters.

We present a detailed characterization of passive, picosecond optical-power-limiting devices using tightly focused beams in thick semiconductor samples. This study of limiting in ZnSe with 30-psec, 532-nm pulses shows that the resulting internal self-action (two-photon absorption plus free-carrier self-defocusing) protects the bulk material from optical damage. Simple scaling relations were det...

Adaptive optical networks using photorefractive crystals.

The capabilities of photorefractive crystals as media for holographic interconnections in neural networks are examined. Limitations on the density of interconnections and the number of holographic associations which can be stored in photorefractive crystals are derived. Optical architectures for implementing various neural schemes are described. Experimental results are presented for one of the...

Nonlinearities of Optical Fibers

Third Order Optical Nonlinearities

V. OPTICAL KERR EFFECT ........................................................................................................................... 11 • BOUND ELECTRONIC OPTICAL KERR EFFECT IN SOLIDS.................................................................................... 11 • RE-ORIENTATIONAL KERR EFFECT IN LIQUIDS ........................................................................