V. Khalfin

Observation of low optical overlap mode propagation in nanoscale indium phosphide membrane waveguides

The authors have developed a nanoscale, rib-loaded waveguide that propagates a low optical overlap mode (LOOM) in which less than 1% of the modal field energy resides in the semiconductor material. Because of the small modal fill factor, the potential for extremely low waveguide propagation loss, on the order of 0.001dB or less, is predicted. Elevated membrane waveguides, 50nm thick with a 50nm thick rib, have been fabricated in InP using a multistep microelectromechanical release process. Both transverse electric and transverse magnetic LOOM propagations have been observed and measurements are compared to theoretical predictions.

Super-high-power operation of 0.98-μm InGaAs(P)/InGaP/GaAs-broadened waveguide separate confinement heterostructure quantum well diode lasers

Record high powers of 16.8 W and 23.5 W have been obtained at CW and Quasi-CW (QCW) operation of 200 μm-aperture Al-free broad waveguide 0.98 μm SCH QW InGaAs(P)/InGaP/GaAs lasers. Some new features of diode laser operation at the super high power regime are considered. Non-thermal, purely current-induced mechanism of power saturation decreases the output powers at P>14 W. Influence of thermal-induced power saturation at high CW currents can be reduced by the stabilization of active region temperature. The main portion (-70%) of active region overheating is associated with a temperature gradient in the copper heatsink. The computed temperature distribution across device is in a good agreement with the spectral and direct measurements of the diode laser temperature. Life-testing at an output power level of 6 W CW and 45 °C has shown only about 6% degradation after more than 1200 hours of operation.

Waveguide collapse In InGaAsP ridge-waveguide lasers with weak lateral optical confinement

Summary form only given. The maximum CW powers for single-mode diode lasers are limited by tolerable current and photon densities in their active regions. The maximum width of a single-mode laser active region is inversely proportional to /spl radic//spl Delta/n/sub B/, where /spl Delta/n/sub B/ is the built-in refractive index step at the active region boundary. In this paper, /spl lambda/=1.5 /spl mu/m InGaAsP/InP SCH 3QW broad-waveguide (600 nm) ridge waveguide lasers with low values of /spl Delta/n/sub B/ (5 - 7/spl times/10/sup -3/) have been investigated.

Development of 1550 nm bipolar cascade lasers

Operation of a 1550 nm, single mode, bipolar cascade laser is demonstrated. Differential quantum efficiency of 86% at room temperature was obtained from two MQW active regions connected in series by a novel tunnel junction.

Non-thermal saturation of P-I characteristics for InP- and GaSb-based broad-contact SCH-QW lasers

Summary form only given. High-power pulsed eye-safe IR laser diodes are currently of increasing interest for applications including range finders and IRCM systems. The output power for InP-based lasers is limited by power-current (P-I) characteristics saturation (rollover effect) rather than by the catastrophic optical damage of the mirror facets as observed for shorter wavelength devices. The current leakage from the quantum well active region has been considered as one of the main reasons of the rollover effect. We present data on the studies of P-I characteristics in the short pulsed regime for broad-contact InP-and GaSb-based separate-confinement heterostructure double-quantum-well (SCH-DQW) lasers emitting in the wavelength range 1.45-1.95 /spl mu/m.

Comparative experimental analysis of jitter performance in extended-cavity semiconductor modelocked lasers

Summary from only given. We show the major influence that the laser resonator has on the phase noise, and hence timing jitter, and for similar cavity Q show the connection of the timing jitter between the semiconductor modelocked laser and that of modelocked fiber lasers.

Low optical overlap mode (LOOM) propagation in InP nanoscale membrane waveguides

A guided low optical overlap mode (LOOM) has a modal confinement factor below 1% and potential for extremely low loss. We demonstrate TM LOOM propagation in planar 50-nm-thick InP membrane waveguides and compare to theory.

Indium-Phosphide-Based Mutation-Designed Optical Waveguides for Application

Altering morphology at scales insensible to optical waves by nanofabrication mutates optical properties of semiconductors. Low-optical-overlap modes (LOOMs) are capable of ultra-low propagation loss, nonlinearity and dispersion in high power and signal processing applications.