C.-P. Chao

Fabrication and analysis of high-contrast InGaAsP-InP Mach-Zehnder modulators for use at 1.55-μm wavelength

A high-contrast ratio, low voltage-length product, multiple quantum well InGaAsP-InP Mach-Zehnder interferometer is demonstrated and analyzed. An on/off ratio of over 40 dB and voltage-length product of 1.8 V-mm were measured, results which are superior to previous reports of similar MQW structures. Using the Lanczos-Helmholtz beam propagation method, we find that the linear and quadratic electrooptic coefficients for InGaAsP quantum wells are r=(3.9/spl plusmn/1.7) pm/V and s=(5.0/spl plusmn/1.5)/spl times/10/sup -19/ m/sup 2//V/sup 2/, respectively. We also demonstrate active optical alignment of the modulator guides using integrated waveguide light emitting diodes.

Low-threshold, high-power, 1.3-/spl mu/m wavelength, InGaAsP-InP etched-facet folded-cavity surface-emitting lasers

A 1.3-/spl mu/m wavelength, InGaAsP-InP folded-cavity, surface-emitting laser with CH/sub 4/-H/sub 2/ reactive ion-etched vertical and 45/spl deg/ angled facets was demonstrated for the first time. Continuous-wave threshold currents of 32 mA have been achieved, with >15 mW CW power for the surface-emitted light. These surface-emitting lasers with two dry-etched facets are suitable for wafer-level testing and for monolithic integration with other InP-based photonic devices.<<ETX>>

A cascadable InGaAsP-InP optoelectronic smart pixel with low switching energy

We demonstrate for the first time a 1.3-/spl mu/m wavelength optoelectronic InGaAsP-InP smart pixel switching circuit using monolithically integrated p-i-n photodiodes and heterojunction bipolar transistors, along with surface-mounted folded-cavity surface-emitting lasers. The circuit functions as a cascadable optical switch with an on/off ratio of 6, and a maximum optical input/output differential gain of 6. At a bit rate of 100 Mb/s, a record low switching energy of 30 fJ was observed while maintaining circuit gain and cascadability. This switching energy is the lowest reported to date for an optoelectronic smart pixel.<<ETX>>

1.3-/spl mu/m wavelength, InGaAsP-InP folded-cavity surface-emitting lasers grown by gas-source molecular-beam epitaxy

A 1.3-/spl mu/m wavelength, strained multiple quantum well InGaAsP-InP folded-cavity surface-emitting laser was fabricated using CH/sub 4/:H/sub 2/ reactive ion etching to form the 45/spl deg/ angled vertical output facet. A pulsed threshold current of 45 mA and a 20% efficiency for the surface-emitted light were achieved for 550 /spl mu/m-long by 5 /spl mu/m-wide devices. The threshold current is the lowest reported for folded-cavity surface-emitting lasers operating at this wavelength, making the devices suitable for many optoelectronic smart pixel and interconnection applications. To our knowledge, this is the first demonstration of an InP-based folded-cavity structure using CH/sub 4/:H/sub 2/ reactive ion etching.<<ETX>>

Monolithic integration of laser and waveguide using a twin-guide structure with absorption layer

We demonstrate for the first time the use of absorption layer to achieve mode control in an InP/InGaAsP integrated twin-guide (TG) laser structure. The In/sub 0.53/Ga/sub 0.47/As layer eliminates the even mode and makes characteristics of the integrated device insensitive to laser cavity length and structure variations, without degrading performance. A record high coupling efficiency of 45% from the TG laser to the integrated passive waveguide is obtained.

Folded-cavity surface-emitting distributed feedback 1.39-um wavelength InGaAsP/InP laser diodes for gas-sensing applications

We have demonstrated distributed-feedback, 1.39 micrometer wavelength InGaAsP/InP, multiple-quantum-well, folded-cavity surface-emitting, laser diodes with a low threshold current of 25 mA. These devices have greater than 45 dB side-mode suppression. Their wavelength tunes continuously with current over an interval of 1.5 angstrom at a rate of 0.11 angstrom/mA (-1.7 GHz/mA). These devices are useful for two-dimensional spectroscopic gas-sensing applications. Employing these compact lasers, we have detected atmospheric water-vapor at 1.3925 micrometer.

Analysis and fabrication of high-contrast InGaAsP/InP Mach-Zehnder modulators for use at 1.55 /spl mu/m wavelength

Summary form only given. A multiple quantum well InGaAsP-InP Mach-Zehnder (MZ) interferometer with a high-contrast ratio of >40 dB, and a low voltage-length product of 1.8 V-mm, is demonstrated and analyzed. Using the Lanczos-Helmhortz beam propagation method (LHBPM), we find that the linear and quadratic electrooptic coefficients for lnGaAsP quantum wells.

1.3 /spl mu/m wavelength, folded-cavity surface-emitting lasers fabricated by CH/sub 4//H/sub 2/ angled facet reactive ion etching

Surface-emitting lasers are useful devices for photonic integrated circuits such as optoelectronic transceivers and smart pixels. In this work, we report the fabrication of 1.3 /spl mu/m wavelength InGaAsP/InP folded-cavity surface-emitting laser (FCSEL) using CH/sub 4//H/sub 2/ 45/spl deg/ angled facet reactive ion etching. A 5 /spl mu/m wide by 550 /spl mu/m long device has a threshold current of 45 mA, which to our knowledge is the lowest reported to date for 1.3 /spl mu/m wavelength FCSELs.