Optical Receiver Circuit Research Articles

SENSITIVITY ANALYSIS OF AVALANCHE PHOTODIODE AND PIN DIODE DETECTORS IN OPTICAL RECEIVERS

<p>This research explained how to establish the optical receiver sensitivity and the link power budget design in terms of quality factor, receiver power and bit error rate (BER) for several values of attenuation at 100km fiber length. The design parameters which were taken into consideration were a constricted transmitter, Zender modulator, attenuator, lowpass Bessel filter, Non-Return-to-Zero modulation format, CW laser, avalanche photodiode (APD) and PIN diode detectors and the type of network coding, Bit Error Rate Analyzer (BER) etc. The objective was achieved using optisystem 7 professional simulation software layout to design the power system budget and optical receiver circuit, the avalanche photodiode and PIN diode were used as the detector. Optisystem simulations were used to determine the optimum power and the receiver sensitivity for several values of attenuation. This research investigated and analyzed the performance of optical receiver at a wavelength of 1550nm. Simulations were made and the Bit Error Rate analyzer values for the various parameters taken. Several values of Q-Factor and Bit Error Rate were tabulated, and the corresponding graphs plotted. There was an improvement in the quality factor, the quality of signal with a low noise value and the extended transmission or propagation time was reduced.</p>

Optical Receiver With Helicity-Dependent Magnetization Reversal

In this paper, we propose helicity-dependent switching (HDS) of magnetization in Co/Pt for an energy efficient optical receiver. Designing a low-power optical receiver for optical-to-electrical signal conversion has proven to be very challenging. Current day optical receivers use a photodiode that produces a photocurrent in response to input optical signals, and power hungry transimpedance amplifiers are required to amplify the small photocurrents. These limitations can be overcome by using light helicity-induced switching of magnetization which can avoid the requirement of photodiodes and subsequent transimpedance amplification by sensing the change in magnetization with a magnetic tunnel junction (MTJ). Magnetization switching of a thin ferromagnet layer using circularly polarized laser pulses has recently been demonstrated which shows a one-to-one correspondence between light helicity and the magnetization state. We use these phenomena to directly switch the magnetization state of a thin Co/Pt ferromagnet layer at the receiver via circularly polarized laser pulses. The circular polarization is controlled in accordance with digital input data which establishes a one-to-one correspondence between the transmitted data and output magnetization state. The Co/Pt layer is used as the free layer of an MTJ, the resistance of which is modified by the laser pulses. Since the output magnetization state is controlled by the input data, the MTJ resistance is directly converted to a digital output signal. Our device-to-circuit level simulation results indicate that HDS-based optical receiver circuit consumes only 0.124 pJ/bit energy, which is much lower than existing techniques.

SENSITIVITY ANALYSIS OF AVALANCHE PHOTODIODE AND PIN DIODE DETECTORS IN OPTICAL RECEIVERS

This research explained how to establish the optical receiver sensitivity and the link power budget design in terms of quality factor, receiver power and bit error rate (BER) for several values of attenuation at 100km fiber length. The design parameters which were taken into consideration were a constricted transmitter, Zender modulator, attenuator, lowpass Bessel filter, Non-Return-to-Zero modulation format, CW laser, avalanche photodiode (APD) and PIN diode detectors and the type of network coding, Bit Error Rate Analyzer (BER) etc. The objective was achieved using optisystem 7 professional simulation software layout to design the power system budget and optical receiver circuit, the avalanche photodiode and PIN diode were used as the detector. Optisystem simulations were used to determine the optimum power and the receiver sensitivity for several values of attenuation. This research investigated and analyzed the performance of optical receiver at a wavelength of 1550nm. Simulations were made and the Bit Error Rate analyzer values for the various parameters taken. Several values of Q-Factor and Bit Error Rate were tabulated, and the corresponding graphs plotted. There was an improvement in the quality factor, the quality of signal with a low noise value and the extended transmission or propagation time was reduced.

An Equivalent Circuit Model for a Ge Waveguide Photodetector on Si

We present an equivalent circuit model with improved accuracy for 1.5-μm germanium waveguide-type vertical photodetectors on a silicon-on-insulator substrate. Our model consists of passive circuit components, two current sources for photogenerated carrier transports, and one noise current source. Model parameters are extracted from electrical S-parameter measurements, TCAD simulations of photodetection frequency responses, and noise measurements. The resulting equivalent circuit model accurately provides photodetection frequency responses at different bias voltages and should be of great use for high-performance optical receiver circuit design.

Highly sensitive 10 Gb/s PAM‐4 optical receiver circuit for three‐dimensional optoelectronic integration

This study presents a 0.35 µm silicon germanium bipolar complementary metal-oxide-semiconductor 10 Gb/s receiver circuit optimised for photonic–electronic three-dimensional integration. Measurements were conducted on a test-chip with a voltage-input signal, which was converted to a current via a series resistor. On the basis of measurement results and using the expected value of the photodetector responsivity of 1 A/W, the PAM-4 circuit consumes 145 mW, sensitivity is −21.8 dBm at 10 Gb/s, and at a bit error rate = 10−9.

Design Optimization of Hybrid-Integrated 20-Gb/s Optical Receivers

This paper presents a 20-Gb/s optical receiver circuit fabricated with standard 65-nm CMOS technology. Our receiver circuits are designed with consideration for parasitic inductance and capacitance due to bonding wires connecting the photodetector and the circuit realized separately. Such parasitic inductance and capacitance usually disturb the high-speed performance but, with careful circuit design, we achieve optimized wide and flat response. The receiver circuit is composed of a transimpedance amplifier (TIA) with a DC-balancing buffer, a post amplifier (PA), and an output buffer. The TIA is designed in the shunt-feedback configuration with inductive peaking. The PA is composed of a 6-stage differential amplifier having interleaved active feedback. The receiver circuit is mounted on a FR4 PCB and wire-bonded to an equivalent circuit that emulates a photodetector. The measured transimpedance gain and 3-dB bandwidth of our optical receiver circuit is 84 dBΩ and 12 GHz, respectively. 20-Gb/s 2 31 −1 electrical pseudo-random bit sequence data are successfully received with the bit-error rate less than 10 −12 . The receiver circuit has chip area of 0.5 mm × 0.44 mm and it consumes excluding the output buffer 84 mW with 1.2-V supply voltage.

Design and Simulation of a PC to PC Communication Network via Fiber Optic Cable

This paper deals with data transfer from one computer to another. The serial ports of the computer are used. MAX 232 is used to convert RS 232 logic to TTL logic and then an optical transmitter circuit is used to transmit data via fiber optic cable. The optical transmitter circuit has an LED which is matched with the cable. At the receiver an optical receiver circuit is used which receives data using a photo diode and a MAX 232 again to convert TTL logic to RS 232 for the serial port at the receiving end computer. The desired baud rate can be set. Although the internet can be used, but due to its time consuming nature, one can implement data transfer using wireless medium, though at a relatively high cost. The need, therefore, is felt for fiber optic communication which is cheaper and more suitable for the task. It is cheaper than wireless medium and is prone to lesser loss as compared to wireless medium.

ENGLISH

Arc fault protection of RF and microwave tubes generally needs short circuiting the high voltage DC plate power supply within few microseconds. A crowbar device is used for the purpose. This conventional method puts enormous stress on the power supply and can cause considerable disturbance in the power lines. Such short circuits of conventional supplies can be avoided by using a suitable solid-state series switch that can open the fault. A trigger circuit for eight IGBTs connected in series is designed, developed and tested for the purpose. Each IGBT floating at different DC voltage imposes strict isolation requirements for individual driver circuits. They must also be suitably isolated from utility power supply. Further, if IGBTs are switched ON at different instants of time (known as jitter), the last IGBT would see a full voltage switch-on and may get damaged. Hence, the jitter among different output signals of different driver circuits should be as low as possible. This paper presents the design requirements of isolation and jitter. The design of optical transmitter, optical receiver and driver circuits would be discussed in detail. Results of four of the channels trigger circuit, assembled and tested to obtain less than100nsec jitter, are highlighted.

Effects of optical communication receiver circuits on Q and BER estimation accuracy

Q factor and bit error rate (BER) estimation based on synchronous and asynchronous sampling have been established as an important method for performance monitoring in optical networks. This study presents a simple model that estimates Q and BER from experimental data using curve fitting under the Gaussian assumption. The model improves estimation accuracy by optimising the receiver analog front end and correcting for sampling errors. The effects of front-end analog amplifiers on the sampling method accuracy have been investigated experimentally by using different optical receivers and post-amplifiers. The results show that the estimated Q and BER track the experimental values over a wide power range. In addition, post-amplifiers operating in the linear region with carefully optimised gain result in a more accurate Q and BER compared to automatic gain control amplifiers.

High performance III/V RTD and PIN diode on a silicon (001) substrate

We report on the fabrication of high performance InP-based devices on an exact (001)Si-substrate. On an InP-on-Si quasi-substrate, the growth of superlattices and low-temperature InAlAs buffer for surface and device layer improvement is investigated. The selected device examples are an InGaAsP PIN diode and an (In)AlAs/In(Ga)As resonant tunnelling diodes. The functionality of these examples relies sensitively on sharp interfaces of ultra thin layers and a high optical quality of epitaxially grown III/V layers silicon substrates. A qualitative improvement is obtained for a low-temperature InAlAs buffer layer grown prior to the of device layers. Based on device models extracted from the fabricated devices a potentially low-cost optical receiver circuit on a Si-substrate is proposed and simulated using HSPICE up to 10 Gbit/s.

A 2.5-Gb/s Receiver OEIC in 0.6-<tex>$muhboxm$</tex>BiCMOS Technology

A monolithically integrated optical receiver circuit in a 0.6-/spl mu/m silicon bipolar complementary metal oxide semiconductor technology with f/sub t/=25 GHz is presented. It incorporates a vertical p-i-n photodetector with a responsivity of 0.36 and 0.26 A/W at 660 and 850 nm, respectively. At these wavelengths, sensitivities of -23.5 and -21.2 dBm, respectively, at a bit rate of 2.5 Gb/s and a bit-error rate of 10/sup -9/ are achieved. The transimpedance gain of the receiver is 18 k/spl Omega/ and overall -3-dB bandwidths of 1.35 and 1.05 GHz at 660 and 850 nm, respectively, are observed.

An optical receiver circuit for on‐line fiber‐optic characteristics monitoring

AbstractA low‐cost optical receiver circuit, which includes a photodiode preamplifier, an active band‐pass filter, and an instrumental amplifier is experimentally achieved. Using the proposed circuit for measurement and on‐line automatic monitoring in this paper, the efficiency of fiber‐optic characteristics monitoring can be enhanced and on‐line noise interference can be suppressed. The transfer functions and frequency response of the optical receiver are derived. The signal‐to‐noise ratio of the on‐line fiber‐optic characteristics monitoring system can be improved using this low‐cost optical receiver. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 354–357, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10605

Differential precoder IC modules for 20-and 40-Gbit/s optical duobinary transmission systems

This paper reports on 20- and 40-Gbit/s differential precoder modules for optical duobinary transmission systems. These precoder modules overcome the speed limit of a conventional precoder by parallel processing. The proposed precoders handle two or four parallel signals before multiplexing with data rates of one-half or one-quarter the transmission bit rate, and the final preceded signal is obtained by multiplexing the precoder output bit by bit, production-level 0.2-/spl mu/m gate-length GaAs MESFET's were used to fabricate the precoders. The precoders are mounted in an RF package. They successfully performed 20- and 40-Gbit/s precoding for the first time, and the 20-Gbit/s precoder achieved a maximum precoding rate of 22 Gbit/s, which is 76% faster than that of the conventional circuit using the same MESFETs. The 40-Gbit/s precoder performs 40-Gbit/s precoding when combined with a 40-Gbit/s multiplexer unit. Twenty-Gbit/s optical duobinary transmitter and receiver circuits using the 20-Gbit/s precoder module successfully generate fully encoded optical duobinary signal at this rate for the first time. These circuits show a receiver sensitivity of -28.6 dBm for a bit error rate of 1/spl times/10/sup -9/.

Clock phase margin of optical fibre receivers

The author analyses the CPM of an optical receiver circuit and shows that there are upper and lower bounds on the transducer resistor of a receiver in order to maintain a specified CPM. Only static phase offsets between clock and data are considered.

Monolithic millimeter wave optical receivers

A single stage monolithic millimeter wave optical receiver circuit was designed and fabricated using a metal-semiconductor-metal (MSM) photodetector and a pSeudomorphic Modulation Doped Field Effect Transistors (SMODFET) on a GaAs substrate for possible applications in chip-to-chip and free space communications. The MSM photodetector and the SMODFET epitaxial material were grown by molecular beam epitaxy (MBE). Device isolation was achieved using an epitaxially grown buffer between the MSM detector layers and SMODFET. The photodetector was designed for maximum absorption at optical wavelength of 770 nm light and the SMODFET impedance matching network was optimized for 44 GHz. The monolithic millimeter wave optical receiver circuit achieved 3 dB gain over a photodetector at 39 GHz, which was the limit of the measurement system. TOUCHSTONE model of the circuit indicated 6.6 dB gain over the photodetector and 5.7 dB total gain including the insertion loss of the photodetector at 44 GHz.

High-performance compact optical WDM transceiver module for passive double star subscriber systems

High-performance transceiver-type optical WDM interface modules with a volume of only 36 cc have been developed for PDS subscriber systems. The new module comprises an optical WDM sub-module, hybrid-integrated transmitter and receiver circuits. In the WDM sub-module, a planar lightwave circuit chip was hermetically sealed together with laser and photodiode chips in order to minimize the size of the transceiver module. The lightwave circuit was formed on an optical-waveguide chip by adopting a high-silica based optical-waveguide technology. The circuit has a 3-dB directional coupler for bi-directional transmission with a 1.3-/spl mu/m wavelength through a single fiber and a wavelength division multiplexer between both 1.3-/spl mu/m and 1.55-/spl mu/m wavelengths. The overall characteristics of the fabricated WDM sub-module achieved were a responsitivity of 0.25/spl plusmn/0.05 A/W, an insertion loss approximately 3 dB at 1.55 /spl mu/m and an isolation of 35 dB between both wavelengths. Optical output power of the fabricated transceiver module was -3.8 dBm. Also, receiver sensitivity of less than -35 dBm with an overload of over -14 dBm were obtained by introducing high-speed automatic gain and threshold control techniques. Thus, an allowable span loss of over 30 dB and an optical dynamic range of over 20 dB were attained. The preamble bit length required to reach stable receiver operation was confirmed to be within three bits.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Compact 10-Gbit/s optical transmitter and receiver circuit packs

Compact wideband 10-Gbit/s optical transmitter and receiver circuit packs are realized using high speed analog and digital GaAs IC's as well as a highly thermally conductive board and appropriately designed small function block modules that employ multichip packaging and resonant cavity mode damping. To achieve a compact receiver, the receiver circuit employs a clamp and peak-detector IC in the high speed analog equalizer amplifier to obtain a constant output direct current level for any mark density imbalance in the number of ones and zeros in the signal and a variable phase-shifter IC in the timing circuit. Realized circuit pack size is 200/spl times/280/spl times/15.24 mm and the power consumption of each pack is about 25 W.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

High-frequency, high-efficiency MSM photodetectors

Metal-semiconductor-metal (MSM) photodiodes with submicron spaced interdigitated Schottky barrier fingers have been developed for applications in monolithic integrated optical receiver circuits capable of detecting a millimeter-wave modulation signal. Each photodetector layer, is designed for optimal absorption about a narrow linewidth centered on a specific wavelength between 700 and 800 nm. The MBE grown layers consist of an Al/sub x/Ga/sub 1-x/As cap layer, to prevent any surface recombination of carriers and to minimize top surface reflections; a thin GaAs absorption layer (375 nm), to achieve a high-frequency response (>39 GHz) by minimizing the collection times of optically generated carriers; and a buried Bragg reflector stack which reflects unabsorbed light back into the GaAs absorption layer. Using this layer design, we are able to fabricate detectors that have millimeter-wave bandwidths without sacrificing quantum efficiency. The measured internal quantum efficiency of an MSM photodiode, fabricated on such a layer structure, was 82% at 5 V and close to 94% at 10 V. >

A High-Reliability 565 Mbit/s Trunk Transmission System

A high-reliability 565 Mbit/s trunk transmission system capable of operating over a 25.5 dB fiber section loss at 1.3 μm is described. Details of the line terminal and repeater design are presented, together with an outline of the integrated circuit design and process. Aspects of the line code and interface choice are also discussed in relation to the optical receiver, transmitter, and supervisory circuits. Finally, systems design aspects are considered and field experience resulting from a system installation spanning 77 km between Birmingham and Derby is reported.

Fiber Optic Video Transmission Employing Square Wave Frequency Modulation

Investigations are carried out on the performance of video transmission systems employing square wave frequency modulation (SWFM). A simple formula for the signal-to-noise ratio (SNR) in the SWFM video transmission systems is derived. The SNR performance is compared to that of frequency modulation (FM) and pulse frequency modulation (PFM). SWFM is shown to display the greatest receiver sensitivity when the fiber 6 dB bandwidth is less than 100 MHz. Video transmission experiments demonstrate the advantages of the SWFM, including 1) degree of simplicity in modulation/demodulation circuits as well as in optical transmitter and receiver circuits, 2) tolerance to nonlinearities in the system, and 3) insensitivity to the fiber baseband frequency-phase characteristics. Both the theoretical and experimental results have made clear the superiority of SWFM optical video transmission systems in application to CATV distribution systems and subscriber loop systems.