A multi-mode interference structure terahertz quantum cascade laser and its manufacturing method

Abstract

The invention relates to a terahertz quantum cascade laser of a multiple-mode interface structure. The terahertz quantum cascade laser comprises a multiple-mode interference wave guiding structure. The multiple-mode interference wave guiding structure comprises a semi-insulating substrate, a buffer layer, a lower contact layer, an active region, an upper contact layer and an upper metal layer in the perpendicular direction from bottom to top in sequence, wherein the active region, the upper contact layer and the upper metal layer form a ridge type structure on the lower contact layer; lower metal layers are arranged on the two sides of the ridge type structure; the upper metal layer forms a multiple-mode wave guide and output wave guides through the wet etching method; the output wave guides are single-mode wave guides and located at the centers of the two ends of the multiple-mode wave guide, and the width of each output wave guide is smaller than that of the multiple-mode wave guide. The invention further relates to a manufacturing method of the THz QCL. By the adoption of the THz QCL of the multiple-mode interface structure and the manufacturing method of the THz QCL, the light-emitting power of the THz QCL can be increased, the quality of an emitted light beam is not reduced, collection efficiency is not reduced, the device is kept small, and cost is reduced.

Description

technical field [0001] The invention relates to a terahertz quantum cascade laser in the technical field of semiconductor optoelectronic devices, in particular to a multi-mode interference structure terahertz quantum cascade laser and a manufacturing method. Background technique [0002] In the electromagnetic spectrum, the terahertz ("THz" for short, 1THz=1012Hz) band refers to the frequency from 100 GHz to 10 THz, the corresponding wavelength is from 3 mm to 30 microns, and the electromagnetic spectrum is quite wide in the range between millimeter wave and infrared light. area. Due to the lack of effective THz radiation generation and detection methods, electromagnetic waves in the THz band have not been fully studied and applied for a long time, which is called the "THz gap" in the electromagnetic spectrum. THz radiation source is a key device for THz frequency band applications. Among the many ways to generate THz radiation, THz quantum cascade laser ("THz QCL") has be...

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Problems solved by technology

However, in order to suppress high-order side mode excitation and improve beam quality, the angle of the wedge-shaped waveguide is generally small (generally less than 5°), which makes the device length too long, which is not conducive to device miniaturization

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