| As a key component of real-time optical information processing, optical computing and optical neural network system, spatial light modulator (SLM) has been developed rapidly since 1980s. In particular, the multiple-quantum-well (MQW) SLM has become to a hot area of optical communication research, with its advantages of fast response, large modulation ratio, high gray scale modulation, low power consumption and so on. Driving circuit is the key to ensure performance of MQW SLM, so that it is great significance to in-depth study. To meet application requirements of MQW SLM, a 64×64 pixel array driver chip of MQW SLM is developed in this paper. The main contents are listed as follows:1. To translate the nonlinear reflectance spectrum of MQW SLM into the corresponding linear electrical-signals directly, a "software preprocessing" concept is put forward. In order to don't take up the hardware resources, the nonlinear optical-signal is converted into the linear electrical-signal using a software fitting method. This method has the advantage of high flexibility and commonality.2.In order to reduce the pixel size, a new method of two-step integral is applied. In this method, the integral-voltage raising process is split into two steps with different clock frequency. The first step is rough-scan, and the second one is final-adjustment. While keeping the resolution of driving voltage, the pixel area of driving circuit is reduced by half, and the clock frequency is reduced.3. By analyzing the generation mechanism of the switching noise, a new structure of switch-network is developed. In this switch-network, the effect caused by switching noise on the capacitor is shifted on the MOS transistor gate, and the switching noise is effectively limited within error tolerance of the current source. Thus the noise on capacitor is isolate, and the integral-voltage precision is improved. The new structure has the advantages of the simpler structure, the lower power dissipation and the higher output precision. 4. A band-gap current source which is independent to the temperature and the power voltage is developed. A reference voltage is generated by using the positive and negative characteristic of the crystal triode itself. The Power Supply Rejection Ratio is improved by using an operational amplifier which constitutes the degenerate loop. The temperature effect on the band-gap current is reduced by using an off chip resistor. The experiment results show that the temperature coefficient of the band-gap current source is 8.7×10-6/℃and it works well within 2.6V-4V power supply.5. The design, simulation, tape-out and the chip test of the driving circuits for the 4x2 pixels,4×4 pixels is completed. After the analyzing pixel structure, performance and precision, an improved circuit structure of 64×64 pixel array driver chip is designed and tested. The experiment results show that the chip can offer the swing of the driving voltage from 0 up to VDD and the resolution of the driving voltage from 0 to 256. Besides, the pixel of driving circuit is compressed into 65μm×65μm, which can be integrated with MQW SLM by flip-chip bonding. In a word, the driver chip could satisfy the design requirements of MQW SLM.
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