Semiconductor laser is also known as laser diode (LD). As early as in 1953, in an unpublished manuscript, John Von Neumann was the first to discuss the possibility of stimulated emission produced in the semiconductor. He considered that stimulated emission can be achieved through the injection of minority carriers to the PN junction, and the transition rates between two Brillouin zones were calculated. After summing up this theory, Bardeen believed that through a variety of methods disturbing co...(more)
In the car field, there is no enterprise specializes in the production of LED lamps. Only a few optoelectronic industries do the research and development in this area. The development bottleneck of domestic LED automotive lamps mainly comes from the following there aspects: First of all, the cost of making LED lamps is too high. The technology of LED chip production is different and the threshold is high. In the crystal growing process, temperature, humidity, power supply and dust elimination ne...(more)
Some low or medium heat transfer, which needs complex temperature control process, thermoelectric cooler can provide great help. And in certain cases, it is the only choice. Although no refrigeration is universal and thermoelectric cooler cannot be applied in all fields, compared with other cooling devices, thermoelectric cooler (see Fig.1) has a lot of advantages. Fig.1Thermoelectric coolerFig.2 Mechanical refrigeration (1) No moving parts: When working, thermoelectric coolers only use electric...(more)
Today I want to introduce the definition of Laser driver. The laser driver, as the name suggests, it is the instrument of the laser control. Generally used to control the semiconductor laser. Including temperature controller and laser diode drive. It is necessary to control the temperature of the device because of the semiconductor device sensitive to temperature, and the semiconductor laser with a constant current source drive, usually it require a current source. The following is the figure of...(more)
At present, there are many kinds of heat sinks, including natural convection, forced convection and liquid cooling. The natural convection radiator can be used in the small power condition, especially when the working current of small thermoelectric coolers is less than 2A. But for most application conditions, natural convection radiator cannot meet the requirement that all heat need to be exhausted, then we need to use forced convection radiators or liquid cooling radiators. In general, radiato...(more)
SNR (SIGNAL-NOISE RATIO) refers to the ratio of signal and noise which is in an electronic device or electronic system. The electronic signals come from external device and need to be processed through the equipment, and the noise is additional signal without rules and does not exist in the original signal, and this noise does not vary with original signal. The unit of signal-noise ratio is dB, and its calculation method is 10 lg (PS/PN), in which PS represents the effective power of the signal ...(more)
One of the attractive features of thermoelectric technology is that it offers an incredible degree of control ability. With a properly tuned controller, it is possible to maintain systems well within 0.1 degree Celsius of set point. The key features are: Precise case temperature control. High stability even for DUTs with dynamic heat load. Very fast thermal response and short temperature setting time. Both cooling and heating functions. Compact. No vibration. Energy saving in many cases. The fol...(more)
LED is the abbreviation of light emitting diode, which is a solid light emitting device of semiconductor. Using light emitting materials of solid semiconductor chips, carriers in semiconductor will composite, cause photon emission and produce light, when the two ends of LED are with forward voltage. LED can directly emit red, yellow, blue, green, green, orange, purple and white light. Our country has huge lighting market of LED and also has strong industrial foundation of lighting. With the deve...(more)
