Spontaneous Oscillation and Self-Pumped Phase Conjugation in
a Photorefractive Polymer Optical Amplifier
A. Grunnet-Jepsen, C. L. Thompson, and W. E. Moerner
Optical processing with photorefractive polymers depends upon
achieving high optical gain, which depends exponentially upon
the product of the interaction length and the gain coefficient.
By using several polymer layers to increase the overall interaction
length and a new high-performance photorefractive polymer composite,
the overall optical one-pass gain becomes as large as a factor
of 5. For a two-layer sample placed in an optical cavity made
with two concave mirrors, spontaneous oscillation due to two-beam
coupling gain has been observed. Because only one pumping beam
is required, this configuration also acts as a self-pumped phase
conjugating mirror with a reflectivity of 13% for an applied
electric field of 75 Volts per micrometer, marking a crucial
milestone for this growing class of optoelectronic materials.