A multichannel integrated circuit intended for readout and analog preprocessing of signals from multielement photodetectors has been designed and evaluated. It is optimized for use with silicon photomultiplier arrays. The chip includes current-signal and voltage-signal processing channels. Except for the front end, all of the channels are identical. Each of them contains a code-controlled current amplifier, an integrator, two digitally controlled variable gain amplifiers, a filter, a peak detector, an output buffer with a level shifter, an amplitude discriminator, two timers, and a control unit. The device is configured and tuned by uploading data via a serial interface. The chip is part of a chipset that also includes a multichannel analog-todigital converter with a buffer memory and voltage reference. This chipset makes it possible to build a fullfeatured multielement photodetector signal-processing system, as well as signal processing systems for multichannel detectors of other types. The integrated circuit is implemented in the 0.35 μm CMOS process. This paper also describes the features of the circuits of the device, analyzes the parameters of several of its basic units, and discusses the test results. 相似文献
The results of a series of studies concerned with formation of epitaxially integrated InGaAs/AlGaAs and AlGaAs/AlGaAs heterostructures with several emitting regions and with investigation of properties of laser diodes based on the above structures operating in the spectral ranges λ = 800–810, 890–910, and 1040–1060 nm are summarized. It is shown that the suggested approach to integration of individual laser structures by the method of the MOVPE epitaxy operates efficiently in fabrication of laser diodes for a wide spectral range on the basis of various types of heterostructures. This approach made it possible to efficiently increase the output power of the laser diodes practically without variation in their mass-and-dimension characteristics. The main advantages of this approach and its limitations are outlined. Epitaxial integration of two laser heterostructures made it possible to increase the differential quantum efficiency by 1.7–2.0 times, while integration of three laser heterostructures increases the differential quantum efficiency by a factor of 2.5–3.0. 相似文献
The results of studying single laser diodes and arrays in the spectral range of 900–1060 nm, fabricated based on InGaAs/AlGaAs epitaxially integrated heterostructures are presented. It is shown that the use of InGaAs/AlGaAs epitaxially integrated heterostructures allows the development of laser emitters with increased power and brightness, operating in the short pulse mode. The results of studying the characteristics of laser-diode arrays (LDAs) fabricated using these heterostructures are presented. 相似文献
A high power laser-thyristor structure providing low current-related and optical losses is developed. The possibility of controlling the lasing turn-on delay time of the laser thyristor in the 8–2600 ns range is demonstrated. The minimum values of the energy and amplitude of the control current-density pulse, required for turning-on the laser thyristor with a peak output power of 28 W, are 1.4 nJ and 0.6 A/cm2, respectively. 相似文献
The paper presents a physical model of a pressure gauge based on polyvinylidene fluoride, a ferroelectric polymer. At pressures of 1–36 GPa, the model agrees with experimental results. 相似文献
A technique of radiation-enhanced thermal oxidation of silicon is developed and implemented in process equipment. Test SiO2 films are grown under exposure to 511-keV gamma-ray photons. Their electrical and radiation performance are evaluated. Basic mechanisms of radiation-enhanced oxide growth are proposed. 相似文献
We have designed, fabricated, and tested a novel photonic band gap (PBG) channel-drop filter (CDF) operating at around 240 GHz. A PBG CDF is a device that allows the channeling of selected frequencies from continuous spectra into separate waveguides through select defects in a PBG structure. It is compact and configurable, and thus, it can be employed for millimeter-wave spectrometry with applications in communications, radio astronomy, and radar receivers for remote sensing and nonproliferation. In this paper we present the design, modeling, and fabrication methods used to produce a silicon-based PBG CDF, and demonstrate its ability to filter the frequency of 240 GHz with a linewidth of approximately 1 GHz and transmission of 25 dB above background. 相似文献
The MOCVD epitaxy has been used to grow the GaInAsP/GaInP/AlGaInP laser heterostructures with a narrow symmetric waveguide and broad asymmetric waveguide. Mesa stripe 100 μm aperture diode lasers emitting at 808 nm were manufactured. It is shown that a SiO2/Si dielectric mirror coating of Fabry-Perot faces of Al-free semiconductor lasers does not result in catastrophic optical mirror damage. It is found that the maximum optical output power of Al-free diode lasers is limited by catastrophic optical damage of the laser heterostructure. Maximum values of optical output power of 5.1 and 9.9 W have been attained in diode lasers with a narrow symmetric waveguide and broad asymmetric waveguide, respectively.