Abstract: The invention discloses a MOS transistor for suppressing generation of a photo-induced leakage current in an active channel region, and an application thereof. A fabrication process comprises: forming a source and a drain at both ends of a substrate by ion implantation, fabricating a gate oxide layer in a middle of an upper surface of the substrate; depositing a polysilicon or a metal on the gate oxide layer to form a gate; depositing an isolation layer above the gate, the source, and the drain; etching contact holes above the source and the drain to extract the source and the drain; depositing the metal on the contact holes above the source and the drain; etching the metal on the drain to isolate the source from the drain; and enabling the metal on the source to directly extend to cover the active channel region, so as to block light rays.

Abstract: A low-noise micro-chip laser includes a diode pump, a gain medium, a nonlinear crystal, and a birefringent material. The gain medium can receive the energy from the diode pump and generate a laser beam at a fundamental wavelength. The nonlinear crystal can generate a frequency-doubled laser beam in response to the laser beam at the fundamental wavelength. To reduce noise in the frequency-doubled laser beam, the birefringent material and the nonlinear crystal in combination are designed to function as a quarter wave plate at the fundamental wavelength.

Abstract: The present invention provides for a low noise, intra-cavity frequency-doubling; diode pumped micro chip laser with wide temperature range comprising pumping diode, gain medium, nonlinear crystal and temperature compensation element. The gain medium pumped by diode generates fundamental wavelength and the nonlinear crystal acts as second harmonic generator. The condition for the laser to work in “low noise operation” is that the nonlinear crystal formed by birefringent materials keeps a quarter wave plate to fundamental wavelength. Since the phase retardation of the plate is strongly relied on temperature, the temperature range of the laser with low noise is narrow. To expend the working temperature range, an additional birefringent material is utilized to compensate variation in phase retardation of the nonlinear material with temperature. It makes the laser in low noise operation in wider temperature range.