Quantum cascade laser with heat conducting passage on substrate

Abstract

A quantum cascade laser with a heat conducting passage on a substrate belongs to the technical field of semiconductor lasers. As for a current quantum cascade laser adopting a normal encapsulation, the radiating effect is very bad, while as for a laser adopting an inverted encapsulation, the welded encapsulation can damage the cavity surface, as a result, the device output performance is reduced, and a big stress is also generated due to the mismatching between a chip and a lattice between heat sinks. The laser provided by the invention adopts the normal encapsulation and adopts the structure that a bent lower electrode is welded with the heat sink, the heat conducting passage is distributed on the heating conducting substrate, and the bending trend of the lower electrode is the same as that of the bottom surface of the heat conducting substrate and that of the surface of the heat conducting passage; moreover, the bent lower electrode covers the bottom surface of the heat conducting substrate and the surface of the heat conducting passage; and heat conducting solder is filled in the heat conducting passage, and the bent lower electrode and the heat sink are welded together through the heat conducting solder. Compared with the current quantum cascade laser adopting the normal encapsulation, the quantum cascade laser provided by the invention has the advantages that the radiating efficiency is improved by more than 30 percent, the electro-optical conversion rate more than 20 percent, and the output power more than 20 percent.

Description

technical field [0001] The invention relates to a quantum cascade laser with thermal conduction channels distributed on a substrate, belonging to the technical field of semiconductor lasers. Background technique [0002] Quantum cascade laser is a unipolar semiconductor laser based on the transition between conduction band and subband of a single carrier (electron) due to the quantum confinement effect. The emission wavelength of the quantum cascade laser covers the middle and far infrared bands of 3~5μm and 8~14μm, and the far infrared band of 15~300μm, covering the NO 2 , CO 2 , CO and other gases characteristic absorption peaks. Quantum cascade lasers are used in both military and civilian fields, such as long-distance optical communications, trace gas detection, and environmental pollution monitoring. [0003] The components of the existing quantum cascade laser are, from bottom to top, the lower electrode 1, the substrate 2, the lower waveguide layer 3, the active ca...

AI Technical Summary

Problems solved by technology

However, in the flip-chip packaged quantum cascade laser, since the distance between the cavity surface of the quantum cascade laser and the solder is only about 5-6 microns, and the excitation voltage of the quantum cascade laser is usually about 10 volts, a single The working current of the tube is about 1 ampere, so it is easy to produce a short circuit

Moreover, during the packaging and welding process of the device, it is easy to cause damage to the cavity surface due to the contamination of the cavity surface, thereby reducing the output characteristics of the device and reducing the life of the device

Furthermore, due to the lattice mismatch between the InGaAs / InAlAs active cascaded gain region, the N-InP or N-InGaAs upper waveguide layer, the highly doped N-InGaAs top layer ohmic contact layer crystal material and the heat sink, there will be great stress

These unfavorable factors also shorten the working life of quantum cascade lasers

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