A large refractive index difference of 0.58 is demonstrated in organic semiconductor films toward advanced optical design of organic optoelectronic devices. Efficient control of light propagation is shown by distributed Bragg reflectors (DBRs) consisting of organic semiconductor films. The DBRs also show photoconductivity, indicating the promising possibility of active control of both charges and light by the organic semiconductors themselves.

Over the past quarter century of organic semiconductor research, refractive index control of organic semiconductor thin films has never been discussed. Daisuke Yokoyama and co‐workers demonstrate a large refractive index difference of 0.58 in organic semiconductor films and fabricated organic photoconductive DBRs (distributed Bragg reflectors) with a reflectivity of >98%. These findings provide us with new additional freedom and strategies in advanced optical design of organic semiconductor devices.

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A 120-ps pulse from a Q-switch, mode-locked Nd: YAG laser was compressed to 1 ps by using two stages of a fiber-grating pulse compressor, an overall pulse-compression rate thus being 120. A laser pulse of 1 ps or 10 ps pulse width was amplified respectively to 0.8 TW or to 1.5 TW peak power by using a Gekko MII Nd:glass laser system. The design and performance of the optical pulse compressor, and detailed performance of amplification for the 1 ps pulse are presented.