• Acta Photonica Sinica
  • Vol. 52, Issue 8, 0814002 (2023)
Zhichang XIA1, Yongai YU2, and Jianhua SHANG1、*
Author Affiliations
  • 1School of Information Science and Technology,Donghua University,Shanghai 201620,China
  • 2Shanghai Oceanhood Opto-electronics Tech Co. Ltd,Shanghai 201206,China
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    DOI: 10.3788/gzxb20235208.0814002 Cite this Article
    Zhichang XIA, Yongai YU, Jianhua SHANG. Output Power and Temperature Stability of Semiconductor Laser Based on STM32[J]. Acta Photonica Sinica, 2023, 52(8): 0814002 Copy Citation Text show less

    Abstract

    With the continuous development of laser technology, semiconductor lasers have made rapid progress in many aspects, such as electro-optical conversion efficiency and output optical power. Because of their small size, high efficiency, low cost, and easy integration with related devices, they are widely used in laser radar, optical sensor detection, beauty, industrial processing and other fields. The central wavelength and output power of semiconductor lasers are easily affected by the driving current and operating temperature. Because the excitation mode of semiconductor laser is direct electrical injection, the stability of injection current directly affects the central wavelength and output power of semiconductor laser. In the process of electro-optical conversion, due to non-radiative composite loss, free carrier absorption and other loss mechanisms, a part of the injected current is inevitably converted into heat. When the working temperature of the laser increases, the reduction of the external differential quantum efficiency and the increase of the threshold current can lead to the reduction of the output power of the semiconductor laser. Temperature rise can also lead to changes in the refractive index and band gap of the semiconductor laser material, thus changing the size of the resonator, and finally the central wavelength of the semiconductor laser will shift red. In addition, the service life of semiconductor laser will be greatly reduced if it works in a high temperature environment for a long time. Excessive temperature rise may reduce the service life by an order of magnitude. In order to solve the problem of driving current and working temperature stability, and to obtain accurate, stable and reliable detection results, a STM32 based medium and low power semiconductor laser driving power supply and temperature control system is designed. The traditional laser power control method is the constant power control based on the photoelectric feedback principle. Due to the serious temperature drift of the photoelectric detector, the power control effect is poor. Traditional laser temperature control uses an integrated semiconductor cooling chip to drive the chip. The circuit is complex and the adjustment time is long. The power control of this design adopts constant voltage control mode. The driving power supply uses a deep negative feedback circuit, and forms a double closed-loop power control with software PID, avoiding the use of photoelectric detectors, which has better power stability in comparison. An H-bridge driving chip and PID algorithm are used to control the temperature of the semiconductor laser. The experimental results show that the driving current stability of this design is excellent, with a stability of about 0.3%, and an accuracy of 0.86%; the temperature adjustment speed is fast, the control accuracy of long-term working temperature is ±0.03 ℃, and the stability can reach 0.18%; the output power of the laser is stable within ±2 mW; the fluctuation range of the central wavelength of the laser is 0.007 5 nm. The power and wavelength under the constant power control mode are also tested. The experimental results show that the power and wavelength under the constant voltage control mode are more stable than that under the constant power control mode. The drive system integrates power control and temperature control, which can meet the working requirements of the laser and can be applied to the same type of semiconductor lasers.
    Zhichang XIA, Yongai YU, Jianhua SHANG. Output Power and Temperature Stability of Semiconductor Laser Based on STM32[J]. Acta Photonica Sinica, 2023, 52(8): 0814002
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