G.G. Mekonnen

InP-based waveguide-integrated photodetector with 100-GHz bandwidth

A waveguide-integrated photodetector is presented, exhibiting a bandwidth of 100 GHz. The responsivity amounts to 0.66 A/W and the PDL is below 0.9 dB. The detector chip is designed to obtain a Bessel filter-shaped transfer characteristic when packaged in a module comprising a 1-mm connector.

Miniaturized waveguide-integrated p-i-n photodetector with 120-GHz bandwidth and high responsivity

A low-capacitance waveguide-integrated photodiode on InP with a minimized absorber length is presented. In order to maintain a high quantum efficiency, an optical matching layer exploiting mode beating effects is employed. Its optimization leads to a twofold enhanced external responsivity of 0.5 A/W at 1.55-/spl mu/m wavelength in accordance with simulation. The reduced p-n junction capacitance enables 3-dB bandwidths up to 120 GHz mainly limited due to carrier transit time effects.

High-Speed Miniaturized Photodiode and Parallel-Fed Traveling-Wave Photodetectors Based on InP

A periodic parallel-fed traveling-wave photodetector (TWPD) with monolithically integrated power splitter is presented. The device exhibits an impedance match to the 50-Omega environment as well as a velocity match between the optical and electrical signals and shows a 3-dB bandwidth up to 85 GHz. The electrical output power reaches +10 dBm at 10 GHz. The device is based on evanescently coupled low-capacitance waveguide-integrated p-i-n photodiodes (PDs) with optimized optical matching layer which reveal a bandwidth of 145 GHz when employed as a stand-alone photodetector

Design and fabrication of 60-Gb/s InP-based monolithic photoreceiver OEICs and modules

An InP-based photoreceiver comprising a waveguide-integrated photodiode and a traveling-wave amplifier is presented, which allows dc-coupled interfacing to subsequent electronics without a bias-T. Getting rid of the bias-T provides cost savings of the receiver operation and improves the available bandwidth, gain, and gain flatness. The redesigned receiver optoelectronic integrated circuit was fully packaged into a pigtailed module with a coaxial 1.85-mm connector. Its optoelectronic conversion capability for nonreturn-to-zero modulated data rates up to 66 Gb/s is shown.

37 GHz bandwidth InP-based photoreceiver OEIC suitable for data rates up to 50 Gb/s

A photoreceiver optoelectronic integrated circuit based on InP with a bandwidth of 37 GHz is presented. The receiver consists of a 50 GHz waveguide-integrated photodiode and a distributed amplifier with a bandwidth of 39.5 GHz, which is composed of four high-electron mobility transistors. A system experiment at 40 Gb/s receiving an return-to-zero coded optical input signal is demonstrated, and a good quality of eye pattern is achieved.

Fast 2 x 2 Mach-Zehnder optical space switches using InGaAsP-InP multiquantum-well structures

We report fast 2/spl times/2 Mach-Zehnder optical space switches by using quantum confined Stark effect in InGaAsP-InP multiquantum-well structures that are ultracompact, require low voltages, and employ a simple RF drive with RC time-constant limited lumped electrodes. Cut-off frequencies in excess of 10 GHz are observed suitable for a variety of fast optical switching applications.<<ETX>>

Parallel-Fed Traveling Wave Photodetector for

A fully packaged traveling wave photodetector (TWPD) with monolithically integrated optical power splitter for high-speed high-power applications in excess of 100 GHz is demonstrated. The detector module provides a responsivity of 0.24 A/W with a polarization dependence of only 0.2 dB at 1.55 mum wavelength and is suitable for the detection of RZ data rates in excess of 80 Gbit/s with unsaturated peak voltages of >0.5 V. Chip-based measurements show a broadband impedance match, a 3 dB bandwidth of 80 GHz and a maximum electrical output power of -2.5 dBm at 150 GHz.

{>}100

For future long-haul communication systems operating at bitrates of 40 Gbit/s and for broad-band mobile access systems using 38- or 60-GHz carrier frequencies, ultrafast photoreceivers have to be provided. Therefore, an integration concept for InP-based optoelectronic microwave monolithic integrated circuits for the 1.55-/spl mu/m wavelength regime is demonstrated, which allows independent optimization of the constituting devices. Two different types of photodetectors (PDs), a waveguide-integrated PIN photodiode (PD) and a top-illuminated metal-semiconductor-metal PD, both having bandwidths of up to 70 GHz, have been developed. These are fabricated together with different amplifier designs employing high electron mobility transistors which exhibit transit frequencies of up to 90 GHz. The application to a 40-Gbit/s broadband photoreceiver for high-bit-rate time-division multiplexing systems is reported, as well as the application to 38- and 60-GHz narrow-band photoreceivers for use as optic/millimeterwave converters in mobile communication systems.

-GHz Applications

A waveguide-integrated photoreceiver, comprising a waveguide-integrated photodiode and a distributed amplifier, is presented. Its optical to electrical conversion capability for nonreturn to zero modulated data rates up to 80 Gb/s is demonstrated. The receiver optoelectronic integrated circuit was packaged into a pig-tailed module with a 1 mm connector output.

Technology of InP-based 1.55-/spl mu/m ultrafast OEMMICs: 40-Gbit/s broad-band and 38/60-GHz narrow-band photoreceivers

A novel fully packaged balanced photoreceiver designed for 40-Gb/s differential phase shift keying (DPSK) applications at 1.55-/spl mu/m wavelength is presented. Based on InP : Fe substrate, two waveguide-integrated photodiodes with spot size converters are monolithically integrated with a distributed amplifier. This configuration leads to a high symmetry of the two optical inputs and avoids interconnection parasitics. The RF output of the photoreceiver is dc-coupled, but the design enables an interfacing to subsequent electronics without external bias-tee by using a negative bias supply at the source terminal of the integrated amplifier. A reduction of system costs and required space will be obtained by this concept. Mounted in a butterfly package, a 3-dB cutoff frequency of 42 GHz is achieved. Return-to-zero (RZ)-DPSK experiments exhibit excellent operation of the balanced photoreceiver over a large dynamic range of optical input power up to +10 dBm. The high-power capability and the clear eye opening at low input power demonstrates the suitability for high performance core and metro systems.