摘要:

A GaInAsP/InP laser (&lgr;g=1.3 &mgr;m) on grooved substrate with a lens‐shaped active layer, in which the current blocking junction is grown exclusively outside of the groove, has been fabricated by single‐step liquid phase epitaxy. This technique is based on the preferential growth effects of InP and GaInAsP on the (100) oriented substrate with [011¯] directed grooves. Under cw operation, low threshold current (38 mA), high output power (40 mW/facet), and high external differential quantum efficiency (56%) are accomplished; fundamental transverse mode operation up to an output of 30 mW/facet is verified. These successful characteristics are realized by the introduction of the inner current confining layer.

ISSN:0003-6951    

DOI:10.1063/1.95257

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Separate confinement heterostructure wafers grown by gas source molecular beam epitaxy have been used to prepare ridge waveguide lasers operating up to 50 °C. Laser threshold currents varied from 45 to 65 mA at room temperature and output powers up to 9 mW have been obtained with the external quantum efficiency of ∼36%. Gain profile measurements indicate excellent material uniformity. Frequency response flat to at least 2 GHz is consistent with the material free of interfacial traps or any capacitive shunt paths.

ISSN:0003-6951    

DOI:10.1063/1.95258

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A thin single crystal of 2‐methyl‐4‐nitroaniline for second harmonic generation experiment is prepared by vapor phase growth. The crystal is used as a high‐index top layer on a tapered slab‐type waveguide. A Nd:yttrium aluminum garnet laser (1.064 &mgr;m) is guided as a fundamental wave. The phase match condition between the fundamental wave (the TE first wave) and the second harmonic wave (the TE second wave) is realized by coincidence of both propagation constants with translational adjustment of the thickness of the waveguide.

ISSN:0003-6951    

DOI:10.1063/1.95259

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Large inversion densities in Zn+have been produced by photoionizing inner‐shelldelectrons with the broadband soft‐x‐ray flux from a 1.06‐&mgr;m laser‐produced plasma. This pumping scheme is an effective technique for rapidly producing large population densities (5×1013cm−3) in the 3d9 4s2 2D5/2upper laser level. These large densities (a) produced laser action on a two‐electron transition from thed‐electron manifold to the outer‐electron manifold at 7478 A˚, (b) allowed the isotope shifts on this relatively weak transition to be measured, and (c) may eventually be transferred to other high lying states in Zn+to produce vacuum ultraviolet lasers.

ISSN:0003-6951    

DOI:10.1063/1.95260

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The threshold current of InGaAsP etched mesa buried heterostructure (EMBH) lasers is strongly influenced by the position of the active layer in the etched mesa. Transmission electron microscopy results are presented which show the presence of a thin planar disorder along the etched 111A interface. Nonradiative recombination of carriers is believed to be responsible for the increased threshold current of EMBH lasers whose active region is bounded by 111A interface. Lasers with threshold current as low as 14 mA at 30 °C have been fabricated by proper placement of the active layer and by optimizing layer thicknesses and doping levels.

ISSN:0003-6951    

DOI:10.1063/1.95261

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Experimental measurements are presented of the gain for a backward Brillouin amplifier using SF6gas, in the pressure range of 3–10 atm, pumped by KrF laser radiation. A small signal gain of 6×10−4cm MW−1, pump depletion of 20%, and an intensity gain of 2.5 have been demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.95262

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We present results of a cleaved‐coupled‐cavity laser analysis which, in contrast to previous studies, incorporates all the following: (1) a model of the gain variation with pumping current and photon energy; (2) the refractive index dependence on the active region injection current; and (3) traveling wave equations for each laser segment. Based on this realistic formulation, we solve for the precise current required by one segment to attain threshold when the current in the other segment is specified for various gap spacings between the segments, and show that device behavior is very sensitive to that dimension. In addition, we calculate quantitatively the spectral tuning and previously unreported jumps from one extreme of the gain spectrum to the opposite extreme in particular current ranges.

ISSN:0003-6951    

DOI:10.1063/1.95263

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Passive mode locking of a 20‐ns pulse duration XeCl laser was achieved. A modulation of 90% and less than 2‐ns pulses are reported using Coumarin 1 and Auramine‐0 dyes as saturable absorbers.

ISSN:0003-6951    

DOI:10.1063/1.95264

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We report the first room‐temperature pulsed oscillation of a GaAlAs/GaAs surface emitting injection laser. A ring electrode of which the outer/inner diameter is 20 &mgr;m/10 &mgr;m has been introduced to distinguish a mirror and Ohmic contact in order to increase the reflectivity. The threshold current was as low as 510 mA at room temperature under pulsed conditions. The cavity length was 7 &mgr;m and single longitudinal mode operation was achieved at &lgr;=8740 A˚ against the temperature variation of 80 K.

ISSN:0003-6951    

DOI:10.1063/1.95265

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Optical levitation using single mode fibers has been experimentally demonstrated. The use of fibers in levitation experiments presents obvious advantages, in particular, concerning the case with which complicated optical paths can be realized without additional optical components. In addition the microsphere can be accurately deposited on the fiber end by simply controlling the optical guided power. This technique has been used to position microlenses self‐centered on the guided mode to improve the coupling efficiency between a semiconductor laser and a single mode fiber.

ISSN:0003-6951    

DOI:10.1063/1.95266

出版商:AIP    

年代:1984

数据来源: AIP