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 /spl mu/m and each LED pixel has 10/spl times/10 /spl mu/m/sup 2/ emitting area. The output power of LED pixel is 50 nW at an operation current of 50 /spl mu/A. 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.

A high speed HBT gate array has been developed for applications requiring data rates up to 5 Gbps. Die size is 2.2 mm×2.2 mm and is packaged in a 68 pin leaded chip carrier with 20 pair of differential I/O signals. Typical power dissipation is 1 to 3 Watts. The array uses three levels of series gating enabling complex logic functions to be implemented efficiently. The top level gate delay is 40 ps for a fanout of one and 60 fF load

The digital and analog lightwave transmission characteristics of p-doped active layer 1.3 mum InGaAsP Fabry-Perot (FP) lasers with semi-insulating current blocking layers were investigated experimentally. For a 1.2 Gbit/s digital lightwave transmission system, it was found that the pulse jitter and the resulting power penalty were strongly dependent on the carrier lifetime of the lasers. This indicates that p-doped active layer FP lasers with decreased carrier lifetimes may be usable in a wider range of gigabit lightwave applications than previously considered. For analog lightwave applications, p-doped active layer FP lasers showed a 3 dB modulation bandwidth of 22 GHz for CW operation. These results suggest that this p-doped active layer FP laser structure is suitable for use in both multigigabit digital and very-high-speed analog lightwave transmission systems. In order to design the facet reflectivities to maximize the modulation bandwidth, a detailed model based on experimental data for high-speed lasers is also presented.

A high speed HBT gate array has been developed for applications requiring data rates up to 5 Gbps. The array uses three levels of series gating enabling complex logic functions to be implemented efficiently. Chip size is 2.2 mm /spl times/ 2.2 mm and is packaged in a 68 pin leaded chip carrier with 20 pair of differential I/O signals. Typical power dissipation is 1 to 3 watts. The top level gate delay is 55 ps for a fanout of one and 60 fF load.<>

The authors report the first implementation of HBT technology on 100 mm OMVPE-grown epitaxial wafers. The electronic characteristics of large area HBT devices with an emitter size of 67/spl times/67 /spl mu/m/sup 2/ are used to measure the uniformity of the epitaxial material. The variations of current gain and V/sub be/ turn-on voltage for such devices are less than 3% and 1%, respectively, across a wafer. This indicates that the characteristic uniformity of epitaxial films grown on 100 mm wafers is comparable with films grown on three-inch wafers. Process induced variation in the device characteristics is measured on small area devices with an emitter size of 1.4/spl times/3 /spl mu/m/sup 2/. The across wafer variations of current gain and V/sub be/ turn-on voltage for these devices are less than 10% and 1%. Circuit yield sufficient for production ramp-up has been demonstrated for gain blocks, prescalers, 14-bit digital-to-analog converters and 8-bit analog-to-digital converters. The success over this array of products demonstrates that the OMVPE-grown 100 mm epitaxial wafers and the HBT fabrication process developed are well suited for a production environment.<>

The authors have fabricated high-speed, low-threshold 1.3 mu m InGaAsP semi-insulating buried crescent lasers with a CW 3 dB modulation bandwidth of 22 GHz and a threshold current as low as 6.5 mA at room temperature. This is the highest 3 dB modulation bandwidth ever reported for the planar-type semiconductor laser. These results were achieved by implementing a submicron photolithographic process in the channel etching to reduce the cavity width and a polyimide dielectric layer under the bonding pad area to minimize the electrical parasitics.< >

We describe the use of split-contact semiconductor laser diodes to suppress multiple-pulsing phenomena in actively mode-locked external-cavity lasers. The laser-diode length is critical for the elimination of multiple-pulse output. With a grating installed in the external cavity, 11.5-ps pulses are generated that have a time-bandwidth product of only 0.30, an important property for use in soliton transmission systems. By using a broadband mirror in place of the grating, nearly transform-limited single pulses of 1.4-ps duration are generated at a 3-GHz repetition rate.

Fe-doped semi-insulating InP layers grown by low-pressure organometallic vapor phase epitaxy with tertiarybutylphosphine have been used as a current block layer for high-speed 1.3-μm InGaAsP buried crescent lasers. The performance characteristics of such lasers are comparable to those of lasers with a PH3-grown Fe-doped semi-insulating InP current blocking layer over a measurement temperature range of 25 to 85 °C. A 3-dB modulation bandwidth of 17.5 GHz has been obtained at room temperature and a cw bias current of 100 mA.

The bit error ratio (BER) performance of a 1.2-Gbit/s lightwave transmission system using 1.3-μm InGaAsP Fabry-Perot (FP) laser diodes with Zn-doped active layers was investigated experimentally. When the laser diodes were tested through a dispersive: fiber, turn-on jitter and mode-partitioning of the lasers contributed to pulse jitter of the optical waveform at the receiver, which in turn led to a dispersion power penalty. It was found that the pulse jitter and the resulting power penalty were strongly dependent on the carrier lifetime of the lasers. Since the doping level of the active layer affects the carrier lifetime, this suggests that doped-active FP laser diodes with a decreased carrier lifetime may be usable in a wider range of gigabit lightwave applications than previously considered.