Fabrication method of ring cavity surface emission difference frequency terahertz quantum cascade laser

Abstract

The invention discloses a preparation method of an annular cavity surface-equipped and difference frequency terahertz-emitting quantum cascading laser structure. The preparation method comprises the following steps of 1, enabling a lower waveguide layer, a lower optical limiting layer, a first active layer, an interval layer, a second active layer, an upper optical limiting layer and an upper waveguide layer to be grown on a substrate in sequence; 2, removing the upper waveguide layer, etching multiple gratings in the upper optical limiting layer in a radial pattern to form a dual-cycle annular grating; 3, performing re-growth of the upper waveguide layer on the etched upper optical limiting layer; 4, etching an annular ridge structure in the upper waveguide layer downwards, wherein the etching depth reaches the lower optical limiting layer; 5, filling the trenches of the etched annular ridge structure with semi-insulated InP: Fe; 6, performing evaporation of a front surface metal electrode on the annular ridge structure, the trenches of which are filled with the semi-insulated InP: Fe, and then performing gold plating; 7, performing thinning and polishing on the substrate, and performing evaporation of a back surface metal electrode on the back surface of the substrate; and 8, etching the metal electrodes to prepare two-stage annular surface metal gratings to complete preparation.

Description

technical field [0001] The invention relates to the technical field of infrared semiconductor optoelectronic devices, in particular to a method for preparing a ring-shaped cavity surface-emitting difference-frequency terahertz quantum cascade laser. The unique feature of this structure is that the epitaxial wafer is made into an annular double-groove structure, and then a two-stage annular metal grating is fabricated on the substrate. Effective extraction of Hertz light; on the other hand, the far-field divergence of THz light can be improved. Background technique [0002] Due to its special spectral position, the terahertz wave with a wavelength of 30-300 μm between infrared and microwave has broad application prospects in spectral imaging, radio astronomy, free space communication, medical treatment and environmental monitoring. At present, the traditionally available high-power terahertz sources are very limited. Some electronic devices are difficult to produce radiation...

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Problems solved by technology

[0003] To sum up the above-mentioned problems that lead to low outcoupling efficiency of terahertz light, this patent proposes a preparation method of ring cavity surface emission difference frequency terahertz quantum cascade laser, which can improve its outcoupling efficiency and realize terahertz efficient extraction of light

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