A Tunable Substrate Emitting Quantum Cascade Laser Array Device

Abstract

The invention discloses a tunable substrate emission quantum cascade laser array device. The tunable substrate emission quantum cascade laser array device includes a substrate, an array device which comprises a plurality of DFB laser units each of which is provided with a ridged waveguide structure, a silicon dioxide layer which covers the entire surface area of the ridged waveguide structures, a front-surface electrode layer which is grown on the silicon dioxide layer and Prague gratings, electrical isolation trenches which are located between the ridged waveguide structures of every two adjacent DFB lasers in the array device, a back-surface metal electrode layer which is grown the lower surface of the substrate, and light exiting windows which are located at the lower surface of the substrate; a lower waveguide layer, a lower limiting layer, an active area, an upper limiting layer, an upper waveguide layer, a cover layer and a highly-doped layer are sequentially grown on the upper surface of the substrate; the highly-doped layer on the ridges of the DFB laser units are provided with secondary sampling Prague grating structures; different Prague gratings have different sampling periods; and the ridged waveguide in each DFB laser unit in the array device is corresponding to one light exiting window.

Description

Technical field [0001] The present invention relates to the technical field of semiconductor optoelectronic devices, in particular to a mid-infrared wavelength tunable substrate emitting quantum cascade array device, more specifically, a secondary distributed feedback quantum cascade laser array substrate prepared based on sampled Bragg grating technology Bottom-emitting device. Background technique [0002] Quantum cascade laser (QCL) is a new type of semiconductor laser based on resonant tunneling and sub-band transition of electrons. Its wavelength can cover the 3 ~ 24um band, which covers such as CO 2 , CO, SO 2 , N 2 , NH 3 The molecular absorption peaks of other gases, so QCL has important application prospects in gas detection and environmental monitoring. [0003] For simultaneous detection of multiple gases in the environment, QCL needs to meet two characteristics: one is single mode; the other is wavelength tunable; in response to the above two requirements, scientists ha...

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Problems solved by technology

[0003] To simultaneously detect multiple gases in the environment, QCL needs to meet two characteristics: one is single-mode; Lasers [C.Gmachl, A.Straub, R.Colombelli, F.Cappasso, et.al, IEEEJ.QuantumElectron.38, 569 (2002)] can achieve single-mode output, but the tuning range is limited; external cavity quantum cascade laser [R.Maulini, M.Beck, J.Faist, andE.Gini, Appl.Phys.Lett.84, 1659(2004)] can achieve the purpose of room temperature pulse width tuning, but the external cavity QCL system is complex, for optical devices, The collimated optical path has high requirements, high cost, and unfavorable system miniaturization and industrialization; although conventional edge-emitting DFB-QCL array devices [BenjaminG.Lee, MikhailA.Belkin, ROssAudet, et.al, Appl.Phys.Lett91, 233301 (2007)] can monolithically integrate multiple DFB lasers with different grating periods to achieve the purpose of single-mode and wide tuning, but it still has the inherent shortcomings of low beam quality and relatively large far-field divergence angle, thus Greatly influenced the practical application of quantum cascade lasers

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