title: Holographic fabricated photonic-crystal distributed-feedback quantum cascade laser with near-diffraction-limited beam quality.
abstract: We demonstrate the fabrication and characterization of photonic-crystal distributed-feedback quantum cascade laser emitting at 4.7 microm. The tilted rectangular-lattice PCDFB structure was defined using a multi-exposure of two-beam holographic lithography. The devices exhibit the near-diffraction-limited beam emission with the full width at half maximum of the far-field divergence angles about 4.5 degrees and 2.5 degrees for stripe widths of 55 microm and 95 microm, respectively. Single-mode emission with a side mode suppression ratio of approximately 20 dB is achieved in the temperature range (80-210 K). The single-facet output power is above 1 W for a 95 microm x 2.5 mm laser bar at 85 K in pulsed operation.
authors.affiliation: Key Lab of Semiconductor Materials Science, Institute of Semiconductors,Chinese Academy of Sciences, PO Box 912, Beijing 100083, China.
authors.forename: Quan-Yong
authors.initials: QY
authors.lastname: Lu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Wang
authors.forename: Jun-Qi
authors.initials: JQ
authors.lastname: Liu
authors.forename: Lu
authors.initials: L
authors.lastname: Li
authors.forename: Feng-Qi
authors.initials: FQ
authors.lastname: Liu
authors.forename: Zhan-Guo
authors.initials: ZG
authors.lastname: Wang