Optical pumping semiconductor laser chip

Abstract

The invention belongs to the field of semiconductor lasers, and particularly relates to an optical pumping semiconductor laser chip. The chip at least comprises a semiconductor chip active region, theactive region is only provided with a group of quantum wells, and the group of quantum wells comprises one or more continuous quantum wells. The invention has the following advantages: since the interval between the adjacent quantum wells is small, carriers can freely pass between the adjacent quantum wells, and the carriers in each well can tend to be uniformly distributed; only one group of quantum wells is arranged, so the thickness of the barrier region is not limited to half wavelength between adjacent periodic quantum wells in the periodic quantum well structure any more and can be setto be large enough, and the pump light can be fully absorbed when passing through the barrier region; a small number of quanta are adopted to enable carriers in each quantum well to realize populationinversion under lower pumping power density, so that the OPSL with lower threshold power density can be obtained; and the front reflection structure is arranged to form an FB cavity in the gain region to improve the laser field intensity at the quantum well, so that the gain of the OPSL chip is significantly improved.

Description

technical field [0001] The invention belongs to the field of semiconductor lasers, in particular to an optically pumped semiconductor laser (Optically pumped Semiconductor Laser, OPSL) chip. Background technique [0002] Semiconductor lasers have the advantages of small size, light weight, high efficiency, wide wavelength range, easy integration, high reliability, and mass production. Therefore, since semiconductor lasers with quantum well structures realized continuous operation at room temperature in the 1970s, It has become an important device in the field of optoelectronic technology. Traditional edge-emitting semiconductor lasers have achieved high power output, but their output spot is elliptical, and the aspect ratio of the spot can reach 100:1 at worst. The beam quality is poor and can only be focused within a short distance. [0003] Optically pumped Semiconductor Laser (OPSL), also known as Semiconductor Disk Laser (SDL), can obtain a circular spot, adopts an exte...

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Problems solved by technology

In optically pumped semiconductor lasers, this feature has changed, and the intensity of the pump light will gradually decay as the chip absorbs it. Most of the existing OPSL chips use a periodic quantum well structure. In the quantum well structure, the number of quantum wells and the thickness of the absorbing layer (including the absorption of pump light by the barrier region and quantum well) in each period are fixed, but the intensity of pump light in each layer of quantum well structure is different. Yes, the number of carriers generated by absorbing the pump light in each cycle of the laser is also different: the carrier concentration in the quantum well close to the pump light source is higher, and the non-radiative recombination coefficient of the carrier with higher concentration increases and decreases. The utilization rate of carriers is improved and waste heat is generated. At the same time, the gain of the quantum well is in a logarithmic relationship with the carrier concentration. The marginal utility of increasing the gain of the quantum well by increasing the carrier concentration shows a decreasing trend; away from the pump The carrier concentration in the quantum well of the light source is low, and the low carrier concentration often cannot reverse the number of particles in the quantum well, which has no effect on the chip gain

Therefore, the periodic quantum well structure is not an ideal structure for OPSL chips

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