摘要:

Room‐temperature continuous‐wave operation of a folded‐cavity surface‐emitting AlGaAs/GaAs laser with transverse junction stripe structure, which has a dry‐etched 45° internal mirror, is demonstrated for the first time. A threshold current of 42 mA and a differential external quantum efficiency of 19% per facet were obtained. A single far‐field lobe and single longitudinal mode emission were also observed.

ISSN:0003-6951    

DOI:10.1063/1.102935

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Picosecond blue light pulse generation by frequency doubling of a gain‐switched GaAlAs laser diode in a proton‐exchanged MgO:LiNbO3waveguide is reported. High‐peak fundamental pulse power of 1.23 W is obtained by employing a laser diode with saturable absorbers. Blue light pulse of 7.88 mW maximum peak power and 28.7 ps pulse width is generated in the form of Cherenkov radiation.

ISSN:0003-6951    

DOI:10.1063/1.102936

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Gain characteristics of Er‐doped silica single‐mode fiber amplifiers are investigated at liquid‐nitrogen temperature (LNT). Liquid‐crystal‐polyester coated Er‐doped fibers are used to prevent an increase in microbending loss of LNT. The maximum net gain and the transmission loss for a 1.535 &mgr;m wavelength are increased at LNT. This increase is explained by a three‐level rate equation taking into account the loss increase. On the other hand, gain characteristics and the transmission loss at 1.552 &mgr;m suggest the change in the amplification mechanism at LNT from a three‐level system to a quasi‐four‐level system.

ISSN:0003-6951    

DOI:10.1063/1.102937

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A numerical study is conducted of a three‐waveguide nonlinear directional coupler. Markedly sharper transmittance characteristics than the well‐known two‐waveguide coupler are obtained at the expense of a higher switching power. Over longer distances transitions from quasi‐periodic to chaotic behavior and back take place as the power is varied.

ISSN:0003-6951    

DOI:10.1063/1.102938

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The characterization and application of a new source of incoherent light for studies of ultrafast processes in condensed matter is described. It is based on the stimulated Raman effect in monomode optical fibers and has a coherence time of ∼80 fs. As an application, we have measured the homogeneous dephasing time of CdSxSe1−x‐doped glasses and obtained a value of 14±4 fs for above‐gap excitation at room temperature.

ISSN:0003-6951    

DOI:10.1063/1.102939

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A three‐terminal quantum‐confined field‐effect double quantum well laser device is proposed. The wavelength shift scheme caused by the field‐induced change in the energy levels is demonstrated. With the current injected and the electric field applied to different wells, wide range wavelength shift can be achieved by changing the applied field.

ISSN:0003-6951    

DOI:10.1063/1.102940

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The transmission and reflection of electromagnetic guided waves by a periodic structure with a delocalized intensity‐dependent nonlinearity was studied using a semianalytical approach. We show that such a nonlocal nonlinear distributed feedback grating can exhibit bistable and switching behaviors depending upon the input intensity and the detuning.

ISSN:0003-6951    

DOI:10.1063/1.102941

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

We report the first operation of a direct diode‐pumped tunable chromium‐doped solid‐state laser. A small alexandrite (Cr:BeAl2O4) crystal was longitudinally pumped by two visible laser diodes. The threshold pump power was 12 mW using theR1line at 680.4 nm for the pump transition, and the slope efficiency was 25%. The measured laser output bandwidth was 2.1 nm.

ISSN:0003-6951    

DOI:10.1063/1.102942

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A monolithic ring resonator of KNbO3was used for efficient frequency doubling of a 856 nm GaAlAs diode laser. A special electronic servo technique was devised to lock the diode laser frequency to the KNbO3cavity so that stable generation of blue output was obtained. With 105 mW of incident near‐infrared power, 41 mW of 428 nm radiation were produced. The conversion efficiency from electrical input power into the diode laser to blue output was ∼10%.

ISSN:0003-6951    

DOI:10.1063/1.102943

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The linewidth enhancement factor &agr; in an In0.2Ga0.8As/GaAs strained‐layer multiple quantum well (MQW) laser has been determined from the spontaneous emission spectra below threshold. The measured &agr; at the lasing wavelength is found to be 1.0 compared to a value of 5 typically observed for InGaAsP/InP double‐heterostructure lasers. The smaller &agr; shows that single wavelength strained MQW lasers may have smaller chirp width under modulation and also smaller cw linewidth.

ISSN:0003-6951    

DOI:10.1063/1.102944

出版商:AIP    

年代:1990

数据来源: AIP