Monolithic integration of an InP/InGaAs four-channel transimpedance optical receiver array

Fully functional four-channel transimpedance receiver array OEICs have been fabricated on 2" diameter InP substrates. Each receiver channel has a bandwidth of 200 MHz and an average input equivalent noise current of around 6 pA/ square root (Hz). The array chip is 3.7 mm*3.2 mm in size and contains 88 components. This is believed to represent the highest level of optoelectronic integration yet reported on InP.<>     

Sensitivity analysis of integrated InGaAs MSM-PD's and HEMToptoelectronic receiver array

A sensitivity analysis is given of a long wavelength optoelectronic receiver array consisting of InAlAs/InGaAs interdigitated Metal Semiconductor Metal photodetectors (MSM-PD's) and a HEMT preamplifier. It is shown that the capacitance varies with the finger width and spacing for a MSM-PD with same active area. Analytical expressions are derived for calculating the sensitivity of the receiver array by means of the equivalent circuit models of the MSM-PD's array and the HEMT. Major noise sources in the receiver array, such as shot noise in the photodetectors, thermal noise in the resistors, gate and drain noises as well as their correlation term in the HEMT, are considered. The influences of geometric parameters of the MSM-PD's and HEMT on the sensitivity of the receiver array are investigated. The optimum gate width of the HEMT is determined for a given MSM-PD array to obtain a high receiver sensitivity. It is also demonstrated that the optical signal related shot noise from the MSM-PD's makes a substantial contribution to the total noise of the receiver array     

A proposed OEIC receiver using MESFET photodetector

An optical receiver configuration based on the concept of using a single optically gated metal-semiconductor-fieid-effect transistor (MESFET) to perform the function of a photodetector and preamplifier has been introduced. The proposed optoelectronic integrated circuit (OEIC) receiver has been analyzed theoretically. A simplified noise model of the receiver has also been developed. Results have been presented for an OEIC receiver based on InGaAs MESFET supposed to be fabricated with matured InGaAs-InP MMIC technology. Theoretical results based on a simplistic noise model reveal that the proposed OEIC receiver has superior performance characteristics over the existing optical receivers     

Low-noise current optoelectronic integrated receiver with internalequalizer for gigabit-per-second long-wavelength optical communications

An equalizer, which is essential in order to improve the sensitivity of receiver optoelectronic integrated circuits (OEICs) at a gigabit-per-second data rate, has been monolithically integrated on an InP substrate with a p-i-n photodiode and a high-impedance high-electron-mobility-transistor (HEMT) amplifier. The receiver operated up to 1.6 Gb/s and showed low noise current characteristics. The minimum noise current is less than 4 pA/√Hz. The sensitivity calculated from the noise current characteristics is -28.4 dBm for 1.6-Gb/s signals. The receiver chip, which was assembled on a ceramic mount, exhibited a sensitivity of -30.4 dBm at 1.2 Gb/s and 1.3-μm wavelength. The performance is as good as those of receiver OEICs with an external equalizer and sufficient for practical use in gigabit-per-second optical communication system     

A gigabit-rate five-highway GaAs OE-LSI chipset for high-speedoptical interconnections between modules or VLSIs

A gigabit-rate five highway interface GaAs optoelectronic LSI chipset has been fabricated for the 0.85 μm wavelength range optical interconnections between modules or VLSIs. The optical sender consists of a high-speed laser driver array LSI having 2 Gb/s maximum operation speed and a tiny laser array. The optical receiver in a GsAs high-speed optical receiver array LSI with a monolithically integrated metal-semiconductor-metal (MSM) photodetector, a high-speed preamplifier, and a decision circuit that has a maximum operation speed of 1.8 Gb/s. The receiver LSI is provided with a new bit-synchronizing circuit and an automatic threshold determination circuit     

可见光通信集成接收机研究

可见光通信技术的推广很大程度上取决于低成本接收机的制备能力,该制备包括光学、光子、电路等元件以及上述元件的集成.文中提出了一种低花费的集成接收机制作方案,提出了一种新型的基于引线键合技术的二维光电检测阵列制备方法,并对光电器件、光学系统的选择,分集接收电路设计思想及其光电集成方案作了详细描述,为下一步的具体制备打下基础.     

A Multibeam SIS Mixer Module for a Focal Plane Array Receiver

The integration of many receiver units into a receiver array is a common method of improvement of imaging systems. This approach, well known in the mm band for Schottky mixer arrays, has not so far been developed for Superconductor - Insulator - Superconductor (SIS) junction mixers, which give the best sensitivity in the short mm wave range and in the submm range. We demonstrate for the first time a practical low noise multibeam receiver module using SIS mixer technology. The basis for the integration of several SIS mixers with a common local oscillator source is given by the saturation of the SIS receiver noise dependence upon local oscillator power. The module comprises three identical SIS mixers integrated with a common local oscillator, coupled through a three branch waveguide directional coupler. The multibeam module has been developed for a focal plane array receiver of the 30 meter radio telescope of the Institut de Radioastronomie Millimétrique (IRAM).     

Characterization of an optoelectronic terahertz beam system

The performance of an optoelectronic terahertz (THz) beam system is described. The transmitter operation is based on the repetitive, subpicosecond laser excitation of a Hertzian dipole antenna embedded in a charged coplanar line. With this transmitter electromagnetic beams of 1/2 cycle THz pulses at a repetition rate of 100 MHz are produced. The associated optoelectronic receiver is gated in synchronism with the excitation of the transmitter by subpicosecond pulses from the same laser source. With this receiver, the 10-nW beams of THz pulses were observed with a signal-to-noise ratio greater than 10000:1. Several sources contributing to the noise of the receiver are discussed, together with ways to reduce them. With an integration time of 125 ms, a signal-to-noise ratio of 1 is obtained for a THz beam with an average power of 10^-16 W. The receiver operates in the sampling mode and has a time resolution of 0.5 ps     

Optoelectronic Integration and Its Impact on System Application

Optoelectronic monolithic integration is preferable for multigigabit transmission systems because of small waveform degradation due to interconnect parasitics in optoelectronic hybrid integration. Implementation of a wavelength division multiplexing subsystem on the optoelectronic integrated chip will further increase the transmission capacity in optical fibers. A five-wavelength integrated distributed feedback laser array with 50 Å lasing wavelength separation has been developed. Multiquantum-wells are promising as a basic structure in future optoelectronic integration. They show high potential in low threshold current laser diodes, high-frequency modulators, and high-speed detectors.     

Design and fabrication of AlGaInP LED array with integrated GaAsdecode circuits

A two-dimensional (2-D) AlGaInP light-emitting diode (LED) array with monolithic integration of one-to-four GaAs MESFET decode circuits has been developed as an image source for portable virtual displays. The epitaxial layers of AlGaInP LEDs with light emission at a wavelength of 605 nm were grown on a semi-insulating GaAs substrate by organometallic vapor phase epitaxy. LED arrays consisting of 240 columns and 144 rows for a total of 34560 pixels were then fabricated on such epitaxial wafers. One-to-four GaAs MESFET decode circuits consisting of eight MESFET's for each decode circuit and a total of 768 MESFET's for a 34 K decode array were fabricated on the semi-insulating GaAs substrate with removal of LED epitaxial layers around the periphery of the LED array. LED arrays with the integrated decode circuits provide a great reduction in I/O terminals. The I/O count of the demonstrated 34 K decode LED array is 104, which is much less than 384 for a comparable array without the integrated decode circuits. The pixel pitch of the LED array is 20 μm and each LED pixel has 10×10 μm² emitting area. The output power of LED pixel is 50 nW at an operation current of 50 μA. The address voltages used to activate the column decode circuits are 3 V for high and -3 V for low, while the address voltages used to activate the row decode circuits are 0 V for high and -3 V for low. The operating voltage of the decode LED array ranges from 3 to 5 V, and the total power dissipation of the decode LED array is less than 16 mW     

Super low-noise GaAs MESFET's with a deep-recess structure

Super low-noise GaAs MESFET's for replacement of parametric amplifiers have been successfully developed by adopting a deep-recess structure. The structure of a 0.5-µm gate in a deeply recessed region with a cylindrical edge shape has enabled reduction of the source resistance to a half of that of conventional flat-type MESFET's. The noise figure was improved by more than 0.5 dB by this reduction of the source resistance, and less than 2.0-dB noise figure has been reproducibly obtained at 12 GHz. The best noise figures were 0.7 dB (14.9-dB gain) at 4 GHz and 1.68 dB (10.7-dB gain) at 12 GHz. The developed MESFET's were applied to two-stage amplifiers of 11.7-12.2-GHz band, and the noise figure obtained was 2.16 dB (T_{e}: 185K) at room temperature and 1.94 dB (T_{e}: 163K) at 0°C. This performance is good enough to replace some of parametic amplifiers.     

Design and performance analysis of InP-based high-speed andhigh-sensitivity optoelectronic integrated receivers

A novel transimpedance optoelectronic receiver amplifier suitable for monolithic integration is proposed and analyzed by exploiting state-of-the-art high-speed MSM photodiodes and HBT's based on lattice-matched InGaAs-InAlAs heterostructures on InP substrates. The projected performance characteristics of this amplifier indicate a high transimpedance (≈3.6 kΩ), a large bandwidth (17 GHz), and an excellent optical detection sensitivity (-26.8 dBm) at 17 Gb/s for the standard bit-error-rate of 10^-9. The latter corresponds to an input noise spectral density, √(i_in²/B), of 2.29 pA/√(Hz) for the full bandwidth. The bandwidth of the amplifier can be increased to 30 GHz for a reduced transimpedance (0.82 kΩ) and a lower detection sensitivity, i.e., -21 dBm at 30 Gb/s. The amplifier also achieves a detected optical-to-electrical power gain of 21.5 dBm into a 50 Ω load termination. The design utilizes small emitter-area HBT's for the input cascoded-pair stage, followed by a two-step emitter-follower involving one small and one large emitter-area HBT's. The design strategy of using small emitter-area HBT's is matched by a low-capacitance novel series/parallel connected MSM photodiode. This combined approach has yielded this amplifier's combined high performance characteristics which exceed either achieved or projected performances of any receiver amplifier reported to-date. The paper also discusses the issues concerning IC implementation of the receiver, including the means of realizing a high-value feedback resistor     

Electron-beam fabrication of GaAs low-noise MESFET's using a new trilayer resist technique

A LO/HI/LO resist system has been developed to produce sub-half-micrometer T-shaped cross section metal lines using e-beam lithography. The system provides T-shaped resist cavities with undercut profiles. T-shaped metal lines as narrow as 0.15 µm have been produced. GaAs MESFET's with 0.25-µm T-shaped Ti/Pt/Au gates have also been fabricated on MBE wafers using this resist technique. Measured end-to, end 0.25-µm gate resistance was 80 ω/mm, dc transconductance gmas high as 300 mS/mm was observed. At 18 GHz, a noise figure as low as 1.4 dB with an associated gain of 7.9 dB has also been measured. This is the lowest noise figure ever reported for conventional GaAs MESFET's at this frequency. These superior results are mainly attributed to the high-quality MBE material and the advanced T-gate fabrication technique employing e-beam lithography.     

A 100-GHz-band heterodyne sis receiver for the trao telescope

A 100-GHz-band Superconductor-Insulator-Superconductor (SIS) receiver has been developed for radio astronomy. The mixer used in this receiver has no mechanical tuning elements, such as a backshort or an E-plane tuner. The SIS junction consists of an array of four Nb/Al-AIOx/Nb junctions in series. The quasi-optic system for this receiver has been designed by frequency-independent matching method. The average DSB receiver noise temperature measured in the frequency range from 85 to 115 GHz is 40 K. The receiver is being successfully operated at the Taeduk Radio Astronomy Observatory in Korea.     

Passive coupling of InGaAsP/InP laser array and singlemode fibres using silicon waferboard

Passive alignment of semiconductor lasers and singlemode fibres has been achieved for the first time using a micro-machined silicon substrate. Mechanical alignment features fabricated on the substrate surface were used to align the active regions of an InGaAsP/InP laser array to four singlemode fibres held in V grooves. Optical coupling efficiencies have been achieved that are comparable to values obtained using the conventional technique of active fibre manipulation. The approach, called silicon waferboard, offers the potential for low-cost optoelectronic device packaging as well as a means for dense hybrid integration of optoelectronic, electronic and optical components required for multifibre, multichip systems.<>     

Monolithic integration of optoelectronic, electronic and passive components in GaAlAs/GaAs multilayers

The monolithic integration of LEDs, detectors, waveguides, resistors and FETs has been demonstrated in GaAlAs/GaAs multilayer structures. The resulting uncommitted optoelectronic integrated circuits have been operated in transmitter, receiver and repeater configurations.     

A 622 Mb/s high-sensitivity monolithic InGaAs-InP pin-FET receiver OEIC employing a cascode preamplifier

A long-wavelength monolithically integrated receiver optoelectronic integrated circuit (OEIC) comprising a low input-capacitance cascode transimpedance preamplifier and a p-i-n photodiode has been demonstrated. The OEIC is fabricated using metal-organic vapor phase epitaxy (MOVPE) grown epilayers and the beryllium ion-implantation technique. The receiver exhibits a sensitivity of -34.7 dBm at 622 Mb/s for BER-10/sup -9/. Using a cascode preamplifier reduces an input capacitance to about one-half of that of an inverter type, which results in the use of a larger feedback resistance of 16 k Omega . The combination of low input capacitance and large feedback resistance reduces the noise current of the receiver and results in high sensitivity.<>     

A Low-Noise 230 GHz SIS Receiver for Radio Astronomy Employing Untuned Nb/AlOx/Nb Tunnel Junctions

A heterodyne receiver based on a ～1/3 reduced height rectangular waveguide SIS mixer with two mechanical tuners has been built for astronomical observations of molecular transitions in the 230 GHz frequency band. The mixer used an untuned array (ωR_nC_j≈3, R_n≈70 Ω) of four Nb/AIOx/Nb tunnel junctions in series as a nonlinear mixing element. A reasonable balance between the input and output coupling efficiencies has been obtained by choosing the junction number N=4. The receiver exhibits DSB (Double Side Band) noise temperature around 50 K over a frequency range of more than 10 GHz centered at 230 GHz. The lowest system noise temperature of 38 K has been recorded at 232.5 GHz. Mainly by adjusting the subwaveguide backshort, the SSB (Single Side Band) operation with image rejection of ≥ 15 dB is obtained with the noise temperature as low as 50 K. In addition, the noise contribution from each receiver component has been studied further. The minimum SIS mixer noise temperature is estimated as 15 K, pretty close to the quantum limit ?v/k～11 K at 230 GHz. It is believed that the receiver noise temperatures presented are the lowest yet reported for a 230 GHz receiver using untuned junctions.     

高灵敏度CMOS光电集成接收机设计

设计了一个由调节型级联跨阻抗放大器(TIA)和双光电二极管(DPD)构成的CMOS光电集成(OEIC)接收机.具体分析了这个光电集成接收机的噪声和灵敏度及其相互关系.接收机中的噪声主要是电路中电阻的热噪声和MOS器件的闪烁噪声.提出了优化接收机灵敏度的方法.通过低成本的CSMC 0.6μm CMOS工艺流片并对芯片进行了测试.从测试眼图可知,该CMOS光电集成接收机可工作在1.25GB/s的传输速率下,灵敏度为-12dBm.     

A 107-Gbit/s Optoelectronic Receiver Utilizing Hybrid Integration of a Photodetector and Electronic Demultiplexer

A novel 107-Gbit/s optoelectronic receiver has been designed using hybrid integration of a photodiode and electronic demultiplexer. Using an ETDM transmitter, we achieve the lowest reported required OSNR for 107-Gbit/s CSRZ-OOK, 21 dB for 10^-3 BER and a 2³¹-1pattern length. Design methodology and performance data are presented.