| The quantum computer greatly improves the information processing speed of the computer due to quantum uncertainty,and it can quickly and effectively decompose information and process information.However,the quantum computer needs to work at low temperature.It is the focus of research to realize the data transmission at low temperature and room temperature and to solve the thermal effect caused by the device during operation.In order to solve this problem,a semiconductor laser with small size and low power consumption can be used.Therefore,the development of a semiconductor laser capable of stable operation at low temperature,low power consumption and high modulation speed is very important to achieve high-speed data transmission at room temperature and low temperature.It can become a breakthrough in the development of quantum computers and an important direction for the development of semiconductor lasers.The InGaAs / GaAs / In GaP 980 nm quantum well laser has been studied to have very low threshold current and power consumption at low temperatures,which plays an important role in further realizing the interconnection of quantum computers at room temperature and low temperature data.In this thesis,some performances of InGaAs / GaAs / In GaP quantum well laser under variable temperature conditions are studied,including the output characteristics,spectral tuning characteristics and the calculation of waveguide refractive index and group refractive index of laser materials at different temperatures under the experimental conditions of 15 K to 300 K.The main content of the thesis is as follows:1.The thesis first introduces the principle and application of semiconductor lasers,and thesis also briefly describes the various experimental devices used in the experiment.2.The thesis also introduces the growth of InGaAs / GaAs / InGaP 980 nm quantum well laser materials,including general knowledge of molecular beam epitaxy(MBE)technology,and the structure and device manufacturing process of In GaAs / GaAs / InGaP 980 nm quantum well lasers.3.The divergence angle of the laser and the output performance of the quantum well laser at variable temperature are studied,including its modulation characteristics,current voltage characteristics,threshold characteristics and power characteristics;the transverse divergence angle of the laser is about 18 degrees,and the vertical divergence angle is about 36 degrees;at the same time,the spectral characteristics of the laser are measured in detail,including the temperature,the cavity length of the laser and the applied current.The cavity length slightlyadjusts the spectrum,at 15 K,the wavelength difference between 1.0 mm and 0.5 mm is 1 nm;for 0.5 mm quantum well laser,the temperature range is 15 K to 300 K,and the wavelength red shift range is about 71 nm;for 1.0 mm quantum well laser,it is found that it can be stably tuned in the current range of 47 m A to 80 mA.At the same time,it is found that the quantum well laser with 1.0 mm cavity length will appear single-mode phenomenon in some cases.The side mode rejection ratio is 24.7 dB,which can also maintain single-mode in other current range.4.The relationship between dispersion,group refractive index and refractive index was studied.Firstly,the change of longitudinal mode spacing is observe through temperature changes:from 0.19 nm at 15 K to 0.24 nm at 300 K,the group refractive index was calculated,and the refractive index and group refractive index is used.The relationship between the conversions calculates that the refractive index of the quantum well laser material waveguide at low temperature(15 K)is about 3.0;at the same time,the standing wave formula is used to calibrate the longitudinal mode series in the laser resonator and observe its temperature dependence Moving,it is also calculated that the refractive index of the laser material waveguide is about2.84.Due to the many factors affecting this method,the experimental error of 5% is acceptable.The refractive index range can be obtained more accurately by two methods. |
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