Optoelectronic Mixer Research Articles

Optoelectronic microwave-range frequency mixing in semiconductor lasers

Optoelectronic mixing of very high-frequency amplitude-modulated signals using a semiconductor laser simultaneously as a local oscillator and a mixer is proposed, Three possible constructions of a monolithically integrated up-or down-converter are considered theoretically: a four-terminal semiconductor laser with dual pumping current/modal gain control, and both a passively mode-locked and a passively Q-switched semiconductor laser monolithically integrated with an electroabsorption pumping current modulator. Experimental verification of the feasibility of the laser-mixer concept is presented. >

Photonic mixers for wide bandwidth RF receiver applications

Optoelectronic mixers can exhibit a very wide bandwidth of operation with significantly reduced third-order intermodulation products. A 20 GHz bandwidth optoelectronic mixer has been constructed and characterized. The third-order intermodulation terms were demonstrated to be more than 70 dB below the IF output. The mixer was then incorporated into a simple superheterodyne receiver architecture, which was shown to have a tangential sensitivity of -66 dBm and a compressive dynamic range of 44 dB. System limitations and possible improvements are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Nonlinear optical microwave interactions in microstrip linear resonators in GaAs

A new optoelectronic mixer parametric amplifier has been fabricated in semiinsulating GaAs using a microstrip linear resonator structure with photoconductive gaps. Schottky contacts were used to produce nonlinear response characteristics, which were characterized with optical and microwave excitations. Harmonic frequencies were optically generated up to 14.6 GHz by illuminating the photoconductive gap with a GaAlAs laser diode modulated near the fundamental resonant frequency of 4.9 GHz. An optical input at frequency frf was mixed with a microwave input at fLO to obtain sum and difference frequencies fLO ± frf. Parametric amplification of the optical input of up to 29 dB was obtained. © 1994 John Wiley & Sons, Inc.

Controlled nonlinearity monolithic integrated optoelectronic mixing receiver

A monolithic integrated optoelectronic mixing receiver with low conversion loss is demonstrated. It consists of a GaAs metal-semiconductor-metal (MSM) photodetector mixer and a two-stage transimpedance preamplifier. By modulating the bias of the MSM photodetector with a local oscillator, the information signal on an optical carrier is down-converted to an electrical intermediate frequency. The mixing receiver nonlinearity can be controlled by simply changing the bias values to the MSM photodetector. The optoelectronic mixer has applications in subcarrier-multiplied lightwave distribution systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Noise performance of a GaAs MESFET as an optical detector and as an optoelectronic mixer in analogue optical links

Noise measurements with a GaAs MESFET employed as a photodetector or as an optoelectronic mixer are reported. Despite its higher noise it is shown that with proper biasing the GaAs MESFET provided a higher carrier-to-noise ratio than a pin photodiode, and as an optoelectronic mixer provided a comparable signal-to-noise ratio to that of a conventional pin and microwave mixer combination. The implications of using GaAs MESFETs in these configurations are discussed.

Monolithic image-rejection optoelectronic up-converters that employ the MMIC process

The authors present very small 30-GHz-band monolithic image-rejection optoelectronic up-converters that employ the HEMT MMIC process for the first time. MMIC HEMT optoelectronic mixers are characterized by their direct photodetection and nonlinear characteristics. It is shown that common-source configurations have higher response than common-drain configurations, and up-converter applications are preferable to down-converter applications based on the HEMT direct photodetection characteristics. These characteristics are used to realize 30-GHz-band monolithic image-rejection optoelectronic up-converters. An in-phase divider and a branch-line hybrid with two HEMT optoelectronic mixers are successfully integrated in an MMIC chip with an area of 1.5 mm*1.1 mm. Fundamental performance is demonstrated and excellent wideband performance, which comes from the well-balanced operation of monolithic integrated circuits, is confirmed. These monolithic optoelectronic mixers can be used to realize compact and cost-effective one-chip optical receivers, for fiber optic links which support millimeter waves. >

Comparison of InGaAs transistors as optoelectronic mixers

Optoelectronic mixing experiments with a range of different InGaAs transistor structures are reported. Results of measurements with both optically and electrically pumped devices show that heterojunction bipolar transistors offer the best performance in terms of the available signal/noise ratio, where values in excess of 30 dB have been obtained.

Fiber-optic microwave transmission using harmonic laser mixing, optoelectronic mixing, and optically pumped mixing

Three fiber-optical link configurations are proposed for use in microwave and millimeter-wave signal transmission. Harmonic laser mixing, optoelectronic mixing and optically pumped mixing are successfully utilized to achieve high carrier frequencies in fiber-optic links. The performance of harmonic laser diode mixers is experimentally investigated in the X-band. The p-i-n photodiode is used as an optoelectronic microwave mixer and an optically pumped microwave mixer, and the microwave characteristics of these mixers are demonstrated. These three fiber-optic link configurations show promise in transmitting microwave and millimeter-wave frequencies. >

Experimental investigation of microwave-optoelectronic interactions in a microstrip ring resonator

Microwave optoelectronic mixing on a semi-insulating gallium arsenide substrate performed by monolithically integrating Schottky diode photodetectors into a microstrip ring resonator is discussed. When operated in the resistive mixing mode, a low frequency difference signal is extracted from the bias pad of the circuit. In the parametric mode, both degenerate and non-degenerate parametric amplification of an optical carrier signal takes place. The circuit shows good potential for application in wide-band fiberoptic systems. >

Theory of avalanche diode harmonic optoelectronic mixer

A simple empirical model is proposed for the multiplication factor of the avalanche photodiode (APD). Using this model closed-form expressions are derived for the conversion loss of APD optoelectronic mixers.

Avalanche diode harmonic optoelectronic mixer

The paper describes the use of an avalanche diode to provide the combined functions of optical detection and harmonic electrical mixing. A simple analytic theory of avalanche optoelectronic mixer operation is presented and used to evaluate the conversion loss and noise performance of the mixer. The theoretical predictions are compared with experimental measurements of harmonic optoelectronic mixing up to the fifth harmonic. Measured conversion losses relative to direct optical detection ranged from 3 dB for fundamental mixing to IS dB for fifth-harmonic mixing. Frequency response limitations are briefly discussed.

GaAs optoelectronic mixer operation at 4.5 GHz

Optoelectronic heterodyne detection of high-frequency intensity modulation signals using a GaAs photoconductive mixer is reported. Flat response for optical modulation frequencies up to 4.5 GHz is observed for downconversion to a 500-MHz intermediate frequency using a low power local oscillator. Heterodyne responsivity was enhanced significantly over direct detection with the same photoconductive detector due to improved contact performance under RF bias.