Laser oscillations of whispering gallery modes in thiophene/phenylene co-oligomer microrings

Abstract

Laser oscillation of whispering gallery modes was observed in microring structures of semiconducting thiophene/phenylene co-oligomer ͑TPCO͒ crystals at room temperature. Microring structures were formed by dry etching from thin film crystals of TPCO. The thresholds for the laser oscillation of a microring and a thin film crystal are 200 and 1400 J/cm 2 for picosecond excitation, respectively. Therefore, the threshold for the microring was reduced to 1 / 7 of that for the thin film crystal. The dramatic reduction of threshold clearly demonstrates the importance of microcavity in making efficient organic semiconductor lasers.

Fabry–Pérot modes and optical waveguide effects in individual thiophene/phenylene co-oligomer nanoneedle crystals

“…The lasing of TPCO crystals has been demonstrated in microdisk structures, occurring in whispering gallery modes (WGMs). [18][19][20] Since the WGMs form on the circumference of the microdisks, they can be regarded as 1D optical nanostructures like ring resonators. In this paper, we have investigated 1D optical confinement features in TPCO nanoneedle crystals.…”

Organic Single-Crystal Light-Emitting Transistor Coupling with Optical Feedback Resonators

“…Within this framework, several efforts have been made to construct a resonator for organic single crystals. Among of the examples were the use of a naturally-formed cleaved facet as a Fabry-Perot resonator202122, microcavities fabricated using electron-beam lithography (EBL) and reactive ion etching (RIE)232425, as well as distributed-feedback cavities prepared using laser ablation method26. As grown single crystals containing natural Fabry-Perot resonator were typically very small in size, and SCLETs fabrication using these crystals was difficult.…”

Ink-jet process for creating fluorescent microdroplet

“…Waveguide type lasers have also been developed with dye-doped optical fibers [43][44][45][46][47][48][49] and fluidic micro-cavities [50][51][52][53][54][55][56][57]. The progress in the laser technology raised interest in micro-resonators such as Fabry-Perot interferometers and ring cavities [58][59][60][61][62][63][64][65][66][67][68]. Theoretical studies on micro-resonators have been conducted extensively in various fields from the spontaneous emission control (Einstein coefficients change) to biosensor development [69][70][71][72][73][74][75][76].…”