Showing papers on "Photodiode published in 1988"

A measurement of the light yield of common inorganic scintillators

Abstract: The light yield in photons per magaelectronvolt of some common inorganic scintillating crystals has been measured with silicon photodiodes. Incident particles are gammas in the 1-MeV region. The light signal was calibrated against 60-keV gammas converted directly in the photodiode depletion layer. Among the tested materials CsI(Tl) gave the highest light yield of 52000 photons/MeV deposited energy. >

Optical chemical sensor based on surface plasmon measurement.

Abstract: A new optical chemical sensor was developed for chemical sensing based on light-excited surface plasmon measurement. Concentration of the chemical species is found in liquid or gas without the help of a reagent but by measuring the resonance condition of the surface plasmon on the sensing metal surface. The resonance condition is given by the dielectric constant of the sample faced on the metal. The developed sensor can be compact and simple, because of the absence of mechanical moving parts, by using multichannel angular light intensity detection with a photodiode array and a Fourier transform optical setup. Experimental results are shown for measurement of ethanol concentration in water. The detection limit for ethanol in water was 10(-4) wt./wt. by the experiments with the developed system.

105-GHz bandwidth metal-semiconductor-metal photodiode

Abstract: The authors report the fabrication and characterization of a metal-semiconductor-metal (MSM) Schottky-barrier photodiode with a measured impulse response shorter than 5 ps and a bandwidth of 105 GHz at a bias voltage of 0.5 V. It is shown that the experimental results are in good agreement with numeric calculations. Because of its high performance and process compatibility with GaAs FETs, this type of photodiode is very well suited for monolithic micro- and millimeter-wave optoelectronic circuits. >

Schottky type photodiodes as detectors in the VUV and soft x-ray range.

Abstract: The quantum efficiencies of semiconductor photodiodes have been measured at photon energies from 5 to 3500 eV. For silicon photodiodes strong radiation-induced effects were found. GaAsP and GaP Schottky diodes show remarkable stability and high quantum efficiency. Use of Schottky diodes for spectroscopic and radiometric measurements is discussed.

A Compact Surface Plasmon Resonance Sensor for Measurement of Water in Process

Abstract: An optical sensor based on surface plasmon resonance (SPR) for water measurement in process has been developed. The optical setup of this sensor is made in a simple and compact way, by the use of a laser diode as a point light source, providing an angularly spread (convergent) beam incident to the sensing part with imaging optics. Multichannel detection by a photodiode array and the Fourier transform optical setup eliminates the need for a mechanical angle scanner or a rotary stage in the system, resulting in a reduction in the size, the weight, and the cost of the sensor. Water concentrations in ethanol were measured by this sensor. Water concentrations of from 0.3% to 10% were obtained. Temperature dependence of the sensor and the method for compensation are discussed.

Compact scanning-force microscope using a laser diode.

Abstract: We describe a compact scanning-force microscope in which the element that senses the amplitude of vibration of a tip interacting with force gradients is the cavity of a single-mode laser diode and its integrally built photodiode.

Solid-state imaging device having photo-electric conversion elements and other circuit elements arranged to provide improved photo-sensitivity

Abstract: A solid-state imaging device including a plurality of photoelectric conversion elements (for example, photodiodes) arranged on a semiconductor substrate so as to form a matrix and read-out means for reading out signal charges which are stored in the photodiodes in accordance with incident light, in a predetermined order, is disclosed in which device the read-out means is made up of a plurality of active elements such as a MOS transistor connected to a photodiode, part of the active elements are used as a pixel amplifier for amplifying the signal charge of the photodiode in such a manner that the signal charge is converted into a current or voltage, the output of the pixel amplifier at a time the signal charge of the photodiode is not applied to the input part of the pixel amplifier and the output of the pixel amplifier at a time the signal charge of the photodiode is applied to the input part of the pixel amplifier are separately stored in a pair of storage means, and the outputs of a plurality of pairs of storage means are successively taken out in accordance with a scanning signal.

High-speed InP/InGaAsP/InGaAs avalanche photodiodes grown by chemical beam epitaxy

Abstract: High-performance InP/InGaAsP/InGaAs avalanche photodiodes (APDs) grown by chemical beam epitaxy are described. These APDs exhibit low dark current (less than 50 nA at 90% of breakdown), good external quantum efficiency (greater than 90% at a wavelength of 1.3 mu m), and high avalanche gain ( approximately=40). In the low-gain regime, bandwidths as high as 8 GHz have been achieved. At higher gains, a gain-bandwidth-limited response is observed; the gain-bandwidth product is 70 GHz. >

New silicon epitaxial avalanche diode for single-photon timing at room temperature

Abstract: A new silicon single-photon avalanche diode (SPAD) with epitaxial structure is presented. The carrier diffusion effect, which has plagued the time response of previous SPADs, is strongly reduced. The resolution obtained, less than 30ps full width at half-maximum, is the highest so far reported in single-photon timing.

Making a photoresponsive array

Abstract: An array for sensing the relative intensity of electromagnetic radiation at a plurality of locations employs a network of photodiodes and non-photoresponsive diodes. A first terminal of each photodiode, e.g. the anode, is electrically connected to a common point which is one terminal of the array. The non-photoresponsive diodes are connected in like-polarity series. The second terminal of each photoresponsive diode is connected to a different connection of non-photoresponsive diodes in the string. The array is scanned with a voltage ramp signal and each change in current flow indicates an illuminated diode. The particular voltage at which current flow changes discloses which photodiode is illuminated. Embodiments of the novel array can be made monolithically without a significant number of conductor cross overs. Monolithic embodiments of the array may be conveniently formed from monocrystalline semiconductors and thin films of amorphous and polycrystalline semiconductors such as amorphous silicon and electrodeposited cadmium telluride-containing semiconductors.

Holographic planar optical interconnect

Abstract: An optical interconnect employing planar volume Bragg hologram technology in two dimensions comprises a dichromated gelatin planar volume Bragg hologram disposed in a glass planar optical path. Multiplexed Bragg plane sets selectively diffract information-bearing light signals such as voice, image, or computer data signals in a VLSI system from a laser diode or LED source coupled to the planar optical path toward high-speed photodiodes. The holographic planar optical interconnect can interconnect up to 1000 different signals between VLSI microelectronic components and systems.

Monolithic optical position encoder with on-chip photodiodes

Abstract: A system that combines light sensors and analog and digital parts on the same CMOS chip has been fabricated. The optical and electrical properties of various photodiodes, which are fully compatible with a standard CMOS technology, are discussed. The current comparators use CMOS-compatible lateral bipolar transistors. The optical encoder also comprises a signal processor for code conversion, a serial or parallel output, and a self-test function. A 14-channel circuit which senses light signals at 880 nm with a power of 0.3-3 mW/cm/sup 2/ has been fabricated. Response time is shorter than 1 mu s at all illumination levels. This circuit operates in the temperature range -55 to +125 degrees C. Its current consumption is 8 mA at 5 V. >

Testing optics by experimental ray tracing with a lateral effect photodiode.

Abstract: We demonstrate a method for testing optics (spherical and aspheric) and other reflecting or transmitting objects. We call this experimental ray tracing. A laser beam is sent through the sample, and its propagation is determined with a lateral effect photodiode. A modified Hartmann test can be performed by measurement of beam location within two planes. Measurement in one plane close to the focus delivers a spot diagram. The method is well suited for testing even strong aspheric optics. As a further use we demonstrate 3-D shape measurement of nonplanar glass plates, e.g., car windshields.

Amorphous silicon/silicon carbide superlattice avalanche photodiodes

Abstract: An a-Si/SiC:H superlattice avalanche photodiode (SAPD) has been successfully fabricated on an ITO/glass substrate by plasma-enhanced chemical vapor deposition. The room-temperature electron and hole impact ionization rates, alpha and beta , have been determined for the a-Si/SiC:H superlattice structure by photocurrent multiplication measurements. The ratio alpha / beta is 6.5 at a maximum electric field of 2.08*10/sup 5/ V/cm. Avalanche multiplications in the superlattice layer yields an optical gain of 184 at a reverse bias V/sub R/=20 V and an incident light power P/sub in/=5 mu W. An LED-SAPD photocouple exhibited a switching time of 4.5 mu s at a load resistance R-1.8 k Omega . >

2.6 μm InGaAs photodiodes

Abstract: We have developed In0.82Ga0.18As p‐n homojunction photodiodes that have a long‐wavelength threshold at about 2.65 μm. A compositionally graded InxGa1−xAs layer accommodates the 2% lattice mismatch between the InP substrate and the In0.82Ga0.18As active layers of the device. At −2 V reverse bias the room‐temperature dark current is 3.5 μA (32 mA/cm2), and the quantum efficiency is 70–75% over the wavelength interval of 2.1–2.6 μm.

Semiconductor laser device

Abstract: PURPOSE:To prevent the variation of output frequency based on frequency modulation by controlling the temperature of a semiconductor laser at a fixed value while stopping or weakening a vibration signal which is minutely vibrating laser driving currents only for a preset period CONSTITUTION:The temperature of a laser diode 11 for a semiconductor laser device is stabilized by a temperature controller 31, and output beams 35, frequency of which is stabilized by stabilizing the temperature, is inputted to a spectroscope 32 A pump optical output and a probe optical output are inputted to photodiodes 16, 17 from the spectroscope 32 A variation component except the variation of oscillation frequency from the laser diode 11 is removed by a divider 15, and inputted to a drive circuit 34 Output beams 35 passing through an optical switch 48 by a half mirror 35a are synchronized with an output from a modulation control circuit 46 stopping or weakening a vibration signal fed to the circuit 34 from a signal source 38 only for a desired period and pass, thus acquiring wavelength stabilizing output beams

Demonstration of an InAsSb strained‐layer superlattice photodiode

Abstract: A photodiode consisting of a p‐n junction embedded in an InAs0.09Sb0.91/InSb strained‐layer superlattice with equal 130‐A‐thick layers was grown using molecular beam epitaxy. This nonoptimized device exhibited photoresponse out to a wavelength of 8.7 μm at 77 K. The resistance and the minority‐carrier diffusion length of the photodiode result in a detectivity (3×109 cm Hz1/2/W) at 7 μm that is within one order of magnitude of the detectivity of the best HgCdTe detectors at that wavelength.

Monolithic integration of a GaInAs p-i-n photodiode and an optical waveguide: modeling and realization using chloride vapor phase epitaxy

Abstract: A theoretical and experimental study is discussed of a p-i-n GaInAs photodiode integrated with inverted-rib InP or GaInAsP waveguides grown on InP substrate. The coupling efficiency between the waveguide and the photodiode is calculated using the beam-propagation method while the initial condition, i.e. the waveguide eigenmode, is calculated by the finite-difference method. The photodiode absorption is calculated as a function of key design parameters, which are the waveguide dimensions, the wavelength and, in the case of heterostructure waveguide, the composition of the quaternary layer. Two classes of device application are foreseen: monitor photodiode and end line receiver. >

Optically powered sensor system

Abstract: An optically powered sensor system includes a plurality of sensors (S₀, S₁, S₂, Sn-1, Sn) connected to a system optical bus (16) that communicates with a system controller (22). Optical energy is transmitted along the bus for distribution to all sensors in the system with return pulses from the various sensors transmitted on the bus (16) to the system controller (22). Each sensor includes a photodiode array (52) for converting optical energy transmitted system-wide by the controller into electrical energy for storage in a storage capacitor (57) associated with each sensor. A transducer (40), such as a thermistor, and a fixed-value reference (44), such as a resistor, are connected to a pulse encoder (42) and, in response to power switched from the capacitor, the pulse encoder produces a series of short-duration pulses having a pulse spacing (T₃-T₄. T₅-T₆) that is dependent upon the fixed value of the reference and the parameter-affected value of the transducer. The pulses are used to drive an optical source for transmitted optical pulses (P₁, P₂, P₃, P₄) from the sensor to the system controller. The parameter value is determined by multiplying the known value of the reference resistor by a time factor ratio which is related by the reference pulse timing and the parameter-affected pulse timing. An optical sensor system is provided in which the measurement of a parameter by each sensor is immune to variations in the electrical components at each sensor.

Optical encoder using sufficient inactive photodetectors to make leakage current equal throughout

Abstract: An optical shaft angle encoder has a plurality of active photodiodes in an array on a semiconductor chip. A rotating code wheel has alternating areas for alternately illuminating or not illuminating the active photodiodes in response to the rotation of the wheel. Errors in the duty cycle involving the end active photodiodes in the array are largely avoided by having a plurality of inactive photodiodes at each end of the array with width and electrical properties effectively the same as the active photodiodes so that leakage current to each end active photodiode of the array is substantially equal to the leakage current to active photodiodes remote from the end of the array. Similarly, leakage current which may affect the duty cycle of individual photodiodes may be minimized by surrounding the individual photodiodes with a reverse biased photodiode junction.

The use of a charge‐coupled device and position sensitive resistive anode detector for multiorder spontaneous Raman spectroscopy from silicon

Abstract: Two state‐of‐the‐art two‐dimensional photon detectors, a high quantum efficiency charge‐coupled device, and a microchannel plate photomultiplier with a position sensitive resistive anode (Mepsicron) have been used to observe spontaneous Raman scattering from multiorder phonon modes of Si in the backscattering geometry. These two detectors and an intensified linear photodiode array are compared using the multiorder spontaneous Raman signal from Si as a weak optical source. An attempt is made to assign the observed Raman scattering peaks in the first‐ through fourth‐order Raman shift regions to known peaks in the density of states of the appropriate Si phonon branches.

Dynamic optical interconnection device for integrated circuits

Abstract: An embodiment of the disclosed device includes: two coupled laser diodes, emitting a light wave which is modulated in frequency and amplitude by electrical signals which control the selection of one among several interconnections and represent a sequence of binary data also included is an optical guide embedded in the surface of a semiconductor substrate and a diffraction grating etched on the surface of the guide and substrate, coupled to the guide to diffract the light in several directions depending on the wavelength as well as photodiodes respectively located in one of the directions where the light can be diffracted, to give an electrical signal representing the binary data transmitted in the direction corresponding to the photodiode. In other embodiments, the photodiodes are coupled to laser diodes by means of a holographic grating.

Planar-structure InP/InGaAsP/InGaAs avalanche photodiodes with preferential lateral extended guard ring for 1.0-1.6 mu m wavelength optical communication use

Abstract: A planar InP-based InGaAs heterostructure avalanche photodiode (APD) with a preferential lateral extended guard ring is proposed. Optimum design and device fabrication are described for the planar-structure APD using various-donor-concentration n-InP avalanche layers, separated from the light-absorbing InGaAs layer. High performance results are low dark current, high speed, low noise, and uniform avalanche gain without edge breakdown. The APD yielded a sensitivity as high as -37.4 dBm for a 2-Gb/s 1.57- mu m wavelength return-to-zero sequence with 10/sup -9/ bit error rate. >

Fiber-optic multigigabit GaAs MIC front-end circuit with inductor peaking

Abstract: The design and performance of a multigigabit optical front-end circuit are discussed. Inductor peaking is applied to the GaAs MIC preamplifiers and a 3-dB down bandwidth of 6.5 GHz, 15.5-pA/ square root Hz averaged input equivalent noise current density from 10 MHz to 6.5 GHz, and transimpedance gain of 57 dB are achieved. A 3-dB down bandwidth of 6.1 GHz is achieved in an optical front-end circuit with a InGaAs p-i-n photodiode. This performance indicates that the optical front-end circuit with inductor peaking is promising for multigigabit optical receivers. >

Monolithic pinHEMT receiver for long wavelength optical communications

Abstract: An AlInAs/GaInAs high electron mobility transistor (HEMT) has been monolithically integrated with an InP/GaInAs pin photodiode for the first time. Transconductance of the integrated HEMT is 270 mS/mm at 1 μm gate length. The high transconductance has resulted in improved receiver sensitivity, −23.7 dBm at 2 Gbit/s.

Method of making a monolithic interleaved LED/PIN photodetector array

Abstract: Interleaved arrays of photoelectronic devices are fabricated utilizing one-step epitaxial growth of all active layers and simple planar processing. Exemplary arrays include interleaved LED transmitters and PIN photodiode receivers that operate at the same wavelength on light that enters the PINs and exits the LEDs along opposite but parallel paths and interleaved arrays of LED transmitters that emit light at two different wavelengths.

Solid-state image sensor

Abstract: PURPOSE:To obtain a stable video signal even over a wide range of temperature region, by providing this device with the following parts: a transparent resin film which is formed on a surface including photoelectric conversion elements, end a shading film which is formed on this transparent resin film so as to shade plural rows of the photoelectric conversion elements. CONSTITUTION:Transfer gate regions 6 are formed between adjacent photodiodes 1 and vertical CCD registers 2. Transfer electrodes 8 are formed through a silicon oxide film 7 respectively on the transfer gate regions 6 and the vertical CCD registers 2, and further an Al layer 9 is formed thereon in an array shape so as to shade respective rows of the transfer gate regions 6 and the vertical CCD registers 2 through the silicon oxide film 7. An insulating film 10 is formed as a protective film over the whole surface including the Al layer 9, and a transparent resin film 11 is formed over the whole surface of the insulating film 10. Arrays of photodiodes 1 are shaded on the transparent resin film 11 to form an optical black. A difference of a dark current hence disappears over a wide range of temperature region and so a stable video signal can be obtained.