An Organic Thin Film Laser Diode: A New and Novel Light Source.

Abstract : This ONR program was focusing on the development of an entirely new diode laser, based upon electroluminescent organic thin films. During these three years, important milestones have been reached towards the demonstration of the first organic laser diode: (i) demonstration of electroluminescence from an organic channel waveguide device fabricated on glass and on Si. (ii) optical gain in excess of 10(4)cm1 measured in a pure solid state conjugated polymer. (iii) fabrication of feedback structures with 0.2 mu resolution. With the synthesis of new compounds and their characterization (determination of HOMO and LUMO levels), the performance of organic light emitting devices could be continuously improved. Current devices exhibit external quantum efficiencies as high as 3 % with a stable aluminum cathode. Output light levels in excess of 45,000 cd/m2 (500,000 cd/m2 in pulsed regime) are measured at this stage and are getting close to the levels required to achieve gain in electrically injected structures. Finally our research efforts have led to the recent demonstration of optically pumped integrated organic laser diodes using several configurations. Simultaneously, we have developed a complete theory of optical absorption in PPV and determined the origin of photo- induced absorption in this material and other pi-conjugated polymers.