High-speed high-precision linear optocoupler based on quantum dot laser and InGaAs detector

Abstract

The invention discloses a high-speed and high-precision linear optocoupler based on a quantum dot laser and an InGaAs detector. The optocoupler comprises an insulating packaging shell with a plurality of pins, two groups of InGaAs photoelectric detectors formed in the insulating packaging shell, a variable-ratio light beam splitter which is formed in the insulating packaging shell and is positioned above the InGaAs photoelectric detector, and a quantum dot laser which is formed in the insulating packaging shell and is positioned above the variable-ratio beam splitter. The InGaAs photoelectric detector and the quantum dot laser are electrically connected with the corresponding pins; the variable-ratio beam splitter is provided with a light inlet used for receiving laser light generated by the quantum dot laser, two light outlets used for emitting the laser light to the two groups of InGaAs photoelectric detectors respectively, and two laser transmission channels formed between the two light outlets and the light inlet.

Description

technical field [0001] The present application relates to the technical field of linear optoelectronic isolation devices, in particular to a high-speed and high-precision linear optocoupler based on quantum dot lasers and InGaAs detectors. Background technique [0002] In the field of signal isolation transmission, because photoelectric isolation uses light signals as the transmission medium through light-emitting devices and photosensitive devices, it has many advantages such as one-way transmission, strong anti-interference ability, long service life, and no contact. It is widely used in various measurement systems. use. Among them, in the field of optical isolation transmission of analog signals, the more commonly used circuits are composed of linear optocouplers, feedback circuits and transimpedance amplifier output circuits. The transmission gain of analog signals depends on the transmission gain of linear optocoupler devices, while the linear optocoupler devices The t...

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Problems solved by technology

[0003] In terms of transmission speed, the internal components of mainstream linear optocouplers at home and abroad all use the transmission scheme of AlGaAs LED light-emitting tube and two PIN photodiodes, which is limited by AlGaAs Due to the transmission speed of the LED light-emitting tube and the influence of the junction capacitance of the PIN photodiode, it is impossible to transmit high-speed analog signals. Typical products such as the IL300 series of the US VISHAY company have a bandwidth of 200KHz, the TIL300 / 300A of the US TI company has a bandwidth of 200Khz, and the HCNR200 / of the US Agilent company In 2001, the bandwidth was 1Mh, and the bandwidth of domestic mainstream linear optocoupler products is also around 200khz. The maximum bandwidth of existing linear optocouplers at home and abroad is only around 1Mhz, and it is impossible to linearly transmit analog signals above 100Mhz or even 1Ghz.

[0004] In addition, in terms of transmission accuracy, among the major foreign manufacturers of linear optocouplers, typical linear optocoupler products such as the IL300 series of the American VISHAY company and the HCNR200 of the American Agilent company / 2001, the TIL300 / 300A series products of American TI Company are all plastic packaging device products. Due to the influence of production process, plastic packaging mold, internal structure and batch difference of photodetectors, the transmission gain and distribution range of each device are relatively large. The transmission gain deviation is greater than 5%. For example, the transmission gain of HCNR200 is 0.85-1.15, the transmission gain of HCNR201 is 0.93-1.07, the transmission gain of IL300 is 0.56-1.65, the transmission gain of TIL300 is 0.75-1.25, and the transmission gain of TIL300A is 0.9-1.1. In addition, The internal glue filling process of foreign plastic packaging devices will affect the distribution of LED light field, resulting in large deviations in transmission gain in high and low temperature environments, which will affect the accuracy of signal transmission

Although the transmission accuracy of linear optocouplers of some domestic manufacturers can be optimized and adjusted through the coupling process, the device structure is complex and the production efficiency is relatively low, which is not convenient for mass production, and cannot solve the technology of transmission accuracy changes caused by LED light field changes in high and low temperature environments question

[0005]Based on the analysis of the above existing technologies, there are still some deficiencies in the transmission bandwidth and transmission accuracy of domestic and foreign linear optocouplers, which cannot meet the linear transmission requirements of high-speed and high-precision analog signals

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