An overview is given of the direct modulation performance of high-speed semiconductor lasers. The high-speed response characteristics are described using a cascaded two-port model of the laser. This model separates the electrical parasitics from the intrinsic laser and enables these subsections to be considered separately. The presentation concentrates on the small-signal intensity modulation and frequency modulation responses, and the large-signal switching transients and chirping. Device-dependent limitations on high-speed performance are explored and circuit modeling techniques are briefly reviewed.

High-speed modulation of semiconductor lasers

Small-signal two-port circuit models of packaged commerical broad-stripe and buried-heterojunction AlGaAs laser diodes are presented. The models are based on the single-mode rate equations, and include the heterojunction I-V and space-charge characteristics. Also included are package and substrate parasitic. The models agree well with measured reflection coefficient and modulation frequency response data, and can be incorporated in standard microwave circuit analysis programs.

Microwave Circuit Models of Semiconductor Injection Lasers

An overview is given of the direct modulation performance of high-speed semiconductor lasers, The high-speed response characteristics are described using a cascaded two-port model of the laser. This model separates the electrical parasitics from the intrinsic laser and enables these subsections to be considered separately. The presentation concentrates on the small-signal intensity modulation and frequency modulation responses, and the large-signal switching transients and chirping. Device-dependent limitations on high-speed performance are explored and circuit modeling techniques are briefly reviewed.

High-speed optoelectronics is a rapidly advancing area driven by the need for higher-speed fiber-optic transmission systems. This area is reviewed, with attention given to high-speed semiconductor lasers, mode-locked semiconductor lasers, and high-speed photodetectors. It is concluded that the prospects look good for expanded use of the large bandwidth capability of optical fiber. This expansion is driven by the increased demands of wideband video and data transmission. It is projected that, with the reduction of transport limitations in semiconductor lasers, bandwidths of semiconductor lasers will soon exceed 30 GHz and operation at 40 Gb/s is possible. Advances in high speed electronics should allow the goal of 40-Gb/s transmission to be realized over the next five years. >

http://ieeexplore.ieee.org/iel2/625/6056/00235697.pdf

Ultrafast optoelectronics

Coherent mixing of optical radiation from a tunable continuous-wave dye laser and a stabilized He-Ne laser was used to generate millimeter-wave signals in GaAs FETs attached to printed-circuit millimeter-wave antennas. The generated signal was further down-converted to a 2-GHz IF by an antenna-coupled millimeter-wave local oscillator at 62 GHz. Detailed characterizations of power and S/N under different bias conditions have been performed. This technique is expected to allow signal generation and frequency-response evaluation of millimeter-wave devices at frequencies as high as 100 GHz. >

Millimeter-wave generation and characterization of a GaAs FET by optical mixing

The performance of optically coupled microwave switching devices for pulse generation or other applications is detailed The bias dependence of the RF power transfer is presented for a range of operating frequencies, thereby establishing the bias conditions required for a given ON/OFF ratio and insertion loss Limits on peak RF power level and pulse repetition rate, as well as limitations arising from harmonic distortion and shot noise, are also examined

Performance of Optically Microwave Switching Devices Coupled

A new optoelectronic microwave switching device is described. The device is composed of a Semiconductor junction diode that is incorporated into a transmission line and illuminated with optical pulses from a semiconductor laser. Switching of microwave signals is achieved by changes in the RF impedance of the diode's high-field region resulting from an optically induced switching between low and high-level avalanche states. Experimental results demonstrating the switching characteristics and speed of this device are presented along with a basic theory of operation. The ultimate capabilities of this device and its advantages over conventional p-i-n diode switches and other optoelectronic switching devices are also discussed.

R.A. Kiehl

Papers

Performance of Optically Microwave Switching Devices Coupled

An Avalanching Optoelectronic Microwave Switch