Takeshi Nagahori

1-Gbyte/sec array transmitter and receiver modules for low-cost optical fiber interconnection

Eight-channel 1-Gbit/s array optical transmitter and receiver modules with 1.3-/spl mu/m wavelength have been developed using a passive-alignment assembly technology and one-chip transmitter and receiver LSIs, to achieve short-haul optical fiber interconnection cost effectively. It features a large dynamic range receiver that can tolerate the power fluctuation in low-cost adjustment-free transmitters and the loss deviation in cascaded optical connectors.

An analog front-end chip set employing an electro-optical mixed design on SPICE for 5-Gb/s/ch parallel optical interconnection

A chip set composed of a laser-diode driver (LDD) and an optical receiver (RCV), which incorporates a full 2D (reshape, regenerate) function, has been developed by using silicon bipolar technology for a four-channel 5-Gb/s parallel optical transceiver. An electro-optical mixed design on SPICE of the LDD and the LD is accomplished by describing the rate equations of the LD as an electrical circuit. This design accommodates easy connectivity of the LDD chip to the LD in the optical transmitter module without the need for adjustment of the optical waveform. A pseudobalanced transimpedance amplifier (TIA) and feedforward automatic decision threshold control (ATC) in the RCV minimize the number of off-chip bypass capacitors, eliminate the need for any off-chip coupling capacitors, and keep crosstalk less than -50 dB and low cutoff frequency less than 80 kHz. A prototype parallel optical transmitter module and a prototype receiver module, based on the chip set, demonstrated asynchronous four-channel 5-Gb/s operation. The chip set has a throughput of 20 Gb/s with a power dissipation of 1.3 W at a 3.3-V supply.

Skewless optical data-link subsystem for massively parallel processors using 8 Gb/s x 1.1 Gb/s MMF array optical module

A high-capacitance, compact, low-cost, and convenient optical data-link subsystem for parallel computers is developed using an 8 Gb/s/spl times/1.1 Gb/s multimode fiber (MMF) array optical module and newly developed data-link IC. Although the subsystem uses an MMF ribbon, parallel data is successfully transmitted over 1 km due to /spl plusmn/15-ns deskew operation of the IC. The subsystem operated stably in a processor networking testbed system of the Real World Computer-1, a newly constructed parallel computer. Random packets are transmitted without any error for over 17.5 h, corresponding to a bit-error rate (BER) of less than 10/sup -15/.

150 Mbits−1 ch−1 12-channel optical parallel interface using an LED and a PD array

An optical fibre parallel interface has been developed for card-cage to card-cage and board-to-board interconnections, representing a practical and promising optical interconnection. For a system design of a 12 channel, 150 Mbits−1 ch−1 optical parallel interface over a distance of 100 m, it is shown that the choice of a long wavelength LED/PD array with graded index optical fibre array meets the requirements for both power budget and skew limitation over this transmission distance. A 7 mm thick compact package transmitter and receiver module was developed, employing a Zn-doped, mesa structure, 1.3μm LED array and an isolated InGaAs PD array. An optical parallel transmission experiment over 100 m was successfully demonstrated using these modules.

Compact multi-channel LED/PD array modules using new assembly techniques for hundred Mb/s/ch parallel optical transmission

Compact 12-channel LED/PD (light emitting diode/photodiode) array modules using novel assembly techniques have been developed for high-speed parallel optical transmission. Optical and electronic devices were mounted on a lateral point and the common submount surfaces, respectively, for high-speed operation and module package miniaturizing. The flip-chip technique by solder bumps was employed for optical array chip bonding, in order to simplify the chip mounting., A 12-channel 150- Mbit/s/ch 100-m parallel optical transmission with small electronic crosstalk has been demonstrated.<<ETX>>

3.125 Gbps 4-channel parallel optical transmitter and receiver for a very short reach 10 Gbps interface

A 3.125 Gbps 4-channel parallel optical transmitter and a receiver have been developed. A 12.5 Gbps throughput for a more than 300 m transmission was obtained with a package size of 15.6/spl times/45/spl times/11.4 mm/sup 3/ and a power consumption of 0.95 W.

A Si bipolar laser diode driver/receiver chip set for 4-channel 5 Gb/s parallel optical interconnection

A chip set of a 4-channel 5 Gb/s laser driver and a receiver uses an electro-optical mixed design with an array of laser diodes. It realizes a parallel optical transceiver module with 20 Gb/s throughput. Optical waveform is not required. Power consumption is 1.3 W.

150-Mbit/s/ch 12-channel optical parallel transmission using an LED and PD array

High speed optical parallel transmissions are attractive for various computer interface and interconnections because of their advantages in transmission capacity, distance, and small cable size over electrical parallel transmission due to low skew and low signal loss in fibers. Moreover, they have advantages in electrical component cost and size over optical serial transmissions, when the bit rate per channel increases to over 100 Mbit/s, because they do not need faster driver/receiver and MUX/DEMUX circuits. Monolithically integrated linear arrays of low drive current, high speed light emitting diodes (LEDs) are particularly useful because of their potential for low temperature sensitivity, high reliability, and low component cost. However, the high speed linear LED arrays reported1,2 have been requiring large drive current of 100-150 mA/ch for sufficient fiber coupled power and speed. This paper reports a 12-channel 150-Mbit/s/ch 100-m optical parallel transmission, using a newly developed low drive current LED and PD array, with as low as 15-mA p-p/ch LED drive current. This high speed optical parallel transmission should meet the demand for upgrading the performance of high speed channels and interfaces for supercomputers and other systems.

3.125 Gbps/channel 4-channel parallel optical transmitter and receiver module with MT-RJ receptacle

This paper describes a 3.125 Gbps 4-channel parallel optical transmitter and a receiver module with MT-RJ receptacle designed for a very short reach OC-192 interface between a DWDM transponder and a core router. The discussion is addressed on the following key features: (1) 4-channel 1310 nm FP-LDs with their anodes and cathodes separated channel-by-channel, (2) 4-channel passive optical alignment technology, (3) inter-channel crosstalk reduction technology in a Si optical bench, (4) low power consumption high speed LD driver and receiver LSIs. The applicability of newly developed 3.125 Gbps/ch 4-channel parallel optical transmitter and receiver module to very short reach application has also been demonstrated through a transmission experiment over a 500 m length of GI-50 MMF (graded-index multi mode fiber).

Data-format-free 622-Mbit/s/ch 12-channel parallel optical transmitter and receiver

A data-format-free 622-Mbit/s/ch 12-channel optical transmitter and receiver have been developed. They provide a skewless PECL interface parallel link for 100-m transmission operating in the ambient temperature range from 0-70/spl deg/C with a 3.3 V power supply.