Terahertz Quantum Cascade Laser with Distributed Bragg Reflection Structure

Abstract

The invention provides a terahertz quantum cascading laser device of a distributed Bragg reflection structure. The terahertz quantum cascading laser device comprises a multi-mode waveguide and DBR grating waveguides formed on the two sides of the multi-mode waveguide respectively. The width of the multi-mode waveguide is at least two times that of each DBR grating waveguide. According to the terahertz quantum cascading laser device, by the adoption of the design that the multi-mode waveguide with a large width and the DBR grating waveguides with a small width are combined, single-transverse-mode laser emission and single-longitudinal-mode laser emission can be achieved simultaneously; moreover, a larger gain area and a higher output optical power are obtained, the quality and collection efficiency of light emergence beams can be improved, and the device is smaller. The DBR grating waveguides realize feedback through periodical change of waveguide widths; upper electrodes and lower electrodes of the DBR grating waveguides can be respectively made of a whole piece of metal, so that injected currents are more uniform, laser wavelength tuning and upper electrode lead bonding are easy to realize, the finished product rate of the device is increased, and operation stability is improved; meanwhile, power loss of terahertz laser is reduced.

Description

technical field [0001] The invention belongs to the technical field of laser semiconductors, and relates to a terahertz quantum cascade laser, in particular to a distributed Bragg reflection terahertz quantum cascade laser based on a multimode interference structure. Background technique [0002] Terahertz (hereinafter referred to as THz, 1THz=10 12 Hz) band refers to the electromagnetic spectrum in which the frequency ranges from 100 GHz to 10 THz, and the corresponding wavelength ranges from 3 millimeters to 30 microns, which is a fairly wide range of electromagnetic spectrum between millimeter waves and infrared light. 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 many THz radiation generation methods, THz...

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Problems solved by technology

[0003] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a terahertz quantum cascade laser with a distributed Bragg reflection structure, which is used to solve the problem that the terahertz laser in the prior art cannot simultaneously lase single transverse mode light and single longitudinal mode light, low output light power and poor quality of outgoing beam

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