R.N. Nottenburg

High efficiency InGaAs/GaAs single-quantum-well lasers using single-step metalorganic chemical vapor deposition

Low-threshold-current single-quantum-well InGaAs/GaAs lasers are fabricated by metalorganic chemical vapor deposition on a nonplanar substrate. By taking advantage of the growth rate and doping differences on different crystal facets during the growth, a buried heterostructure laser with natural current blocking p-n-p-n junction is formed by a single growth step. Threshold currents as low as 1.0 mA under pulsed operation and 1.2 mA under continuous-wave operation are obtained for uncoated lasers at room-temperature. The lasers showed high external quantum efficiency (80%) and high T/sub 0/ (150 K). High reflection coated laser (95%/95%) have CW threshold current as low as 0.28 mA.<<ETX>>

DC to 2.5 Gb/s*4 p-i-n/HBT optical receiver array with low crosstalk

A multichannel optical receiver with an In/sub 0.53/Ga/sub 0.47/As p-i-n photodetector array and a monolithic transimpedance amplifier array fabricated in AlGaAs/GaAs HBT (heterojunction bipolar transistor) technology were demonstrated. Both flip-chip rear-illuminated and wire-bonded front-illuminated detector configurations were implemented. The transimpedance was 65 dB Omega , and the 3-dB bandwidth was measured to be 2.3 GHz. By using series feedback, the transimpedance gain of each cell was matched to within 0.5 dB, and the entire array operated from a single 5-V supply. A low interchannel crosstalk of less than -40 dB was measured up to a data rate of 2 Gb/s.<<ETX>>

High-speed large-signal digital modulation of three-terminal low-threshold strained InGaAs/GaAs lasers

We present large-signal digital modulation of very low-threshold strained InGaAs/GaAs single quantum well (SQW) lasers with monolithically integrated intracavity modulators. The voltage controlled intracavity modulator was driven from a simple emitter-follower using a single NPN transistor. Modulation response mas obtained from dc to 1 Gbit/s with a modulation efficiency of 27% and modulation depth of nearly 100%. A bit-error-rate (BER) lower than 10/sup -11/ was measured at 1 Gbit/s with an input signal swing of only 110 mV. We demonstrate the suitability of these devices for ultrabroad-band optical interconnection applications.<<ETX>>

Three-terminal bistable low-threshold strained InGaAs/GaAs laser grown on structured substrates for digital modulation

Strained InGaAs/GaAs quantum-well three-terminal lasers with monolithically integrated intracavity modulators were fabricated using low threshold current structures formed by the temperature engineered growth (TEG) technique. An on-off switching ratio of 556 was obtained for a 30-mV change in absorber voltage. An optical power contrast ratio of 7.5 was measured with a total DC power consumption of 25.3 mW. These results show a great improvement in the digital (on-off) switching performance of three-terminal lasers with intracavity modulators.<<ETX>>

Monolithic retimed receiver array with dynamic reference level comparator for 4/spl times/2 Gb/s synchronous optical data link

A DC-coupled 4-channel synchronous optical receiver with 8-Gb/s aggregate throughput has been designed using a monolithic silicon bipolar IC and an InGaAs p-i-n photodiode array. Each channel employs a positive feedback structure to dynamically generate threshold voltage in the decision which enables single-ended-to-differential signal conversion without coupling capacitors or reference voltage subcircuits. Power dissipation is 865 mW at -5.5 V supply voltage.

Low-threshold InGaAs/GaAs single-quantum-well lasers using single-step metalorganic chemical vapor deposition

Low threshold current single quantum well InGaAs/GaAs lasers are fabricated by metalorganic chemical vapor deposition on a nonplanar substrate. By taking advantage of the growth rate and doping differences on different crystal facets during the growth, an almost- buried heterostructure laser is made by a single growth step. Threshold currents as low as 1.0 mA under pulsed operation and 1.2 mA under continuous-wave operation are obtained for uncoated lasers at room-temperature. The lasers showed high external quantum efficiency (80%). High reflection coated laser (95%/95%) has a cw threshold current as low as 0.28 mA.

High-efficiency three-terminal laser array for optical interconnect

Strained InGaAs/GaAs quantum well three terminal lasers with monolithically integrated intracavity modulators were fabricated using low threshold current structures formed by the temperature engineered growth (TEG) technique. An on-off efficiency ratio of 556 with optical power contrast ratio of 7.5 was measured with a total DC power consumption of 25.3 mW. Preliminary digital modulation shows bit error rate (BER) lower than 10-16 at 500 Mb/s. A theoretical analysis of the dynamic behavior of this device shows potential operation of 6.6 Gb/s with low inter-symbol interference.