摘要:

We report the first measurements of optical absorption saturation in GaAs/GaAlAs multiple quantum well (MQW) structures at room temperature near the heavy hole exciton peak. Linear absorption shows distinct exciton peaks at room temperature in the MQW and we deduce this is because the confinement increases exciton binding energy without increasing LO phonon coupling. This room‐temperature MQW absorption also saturates more readily than that in a comparable GaAs sample; the measured saturation intensity is 580 W/cm2with a recombination time of 21 ns in a MQW with 102‐A˚ GaAs layers. From this we predict a nonlinear refraction coefficientn2∼2×10−5 cm2/W. This large nonlinearity should permit room‐temperature optical devices compatible with laser diode wavelengths, materials and power levels.

ISSN:0003-6951    

DOI:10.1063/1.93648

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

We report the first observation of the resonance phenomena on the bias current dependence of the amplified light output for AlGaAs double heterostructure laser. We also show that this resonance phenomenon is mainly caused by the change in the refractive index of the active layer due to the bias current change in terms of the simple theoretical calculations taking into account the effect of the refractive index change in the active layer.

ISSN:0003-6951    

DOI:10.1063/1.93649

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The width of XeCl laser pulse from a discharge laser has been ’’temporally tuned’’ from 5 ns to less than 500 ps using saturable absorber dyes. A maximum pulse shortening of ≊20 has been achieved in a single pass, single stage saturable absorber pulse compression scheme. Pulse shortening characteristics were found to be reproducible for single shot and repetition rate operation.

ISSN:0003-6951    

DOI:10.1063/1.93650

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Optical and magneto‐optical studies MnSb films substituted with 20 at. % of cobalt have been carried out. The results suggest the possibility of these being considered as potential candidates for magneto‐optic storage.

ISSN:0003-6951    

DOI:10.1063/1.93651

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

We report the results of a theoretical and experimental investigation of a passive (self‐pumped) phase conjugate mirror. This device is based on real time holography in materials which allow a spatial phase shift between the refractive index grating and the light interference pattern. An imaging experiment is reported showing the phase conjugating nature of the device. The holographic medium used was a single crystal of barium titanate.

ISSN:0003-6951    

DOI:10.1063/1.93652

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

We report the first observation of radiation from coherently excited thin‐film plasmons of definite wave vector. With two noncollinear CO2laser beams incident on a 20‐&mgr;m‐thick film ofn‐InSb, a difference frequency radiation at ∼100 cm−1was generated, with a resonance at the plasma frequency. Previous theory had indicated than thin‐film plasmons of definite wave vector could be coherently excited with a longitudinal driving force produced at the difference frequency of two laser beams. This thin‐film plasmon is partially transverse and radiates efficiently. The observed difference frequency generation as a function of angle and difference frequency follows the theoretical predictions.

ISSN:0003-6951    

DOI:10.1063/1.93653

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Phase noise in semiconductor lasers has been investigated by many authors in the range of low frequencies (<1 MHz). In this letter we present for the first time phase noise measurements extended up to frequencies greater than 1 GHz. Experimental results showing the power spectral densityS&fgr;˙(&ohgr;) of the instantaneous frequency &fgr;˙(t) and the variance &sgr;2[&Dgr;&tgr;&fgr;(t)] of the phase shift &Dgr;&tgr;&fgr;(t) are presented. The peculiar behavior ofS&fgr;˙(&ohgr;), which presents a sharp peak at the same frequency of the amplitude noise peak, can account for the excessive broadening of the linewidth of single‐mode injection lasers.

ISSN:0003-6951    

DOI:10.1063/1.93654

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Nematic as well as phase‐change guest‐host liquid crystal displays are shown to be dual‐frequency addressable by using liquid crystalline hosts with suitable static and dynamic dielectric properties, thus rendering them multiplexable. Positive as well as negative optical contrasts and fast turn‐off times can be achieved.

ISSN:0003-6951    

DOI:10.1063/1.93655

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

The development of the anti‐Stokes to Stokes ratio of spontaneous Raman scattering in silicon is measured during annealing with a 10‐ns laser pulse. Raman measurements with weak UV probe pulses avoid averaging over the penetration depth of the annealing pulses. The data suggest that the surface temperature rises above the melting point for exposure energies greater than 0.35 J/cm2. The absolute temperature inferred from the Raman experiments are subject to some uncertainty because of a lack of information on the temperature dependence of the Raman scattering cross sections.

ISSN:0003-6951    

DOI:10.1063/1.93639

出版商:AIP    

年代:1982

数据来源: AIP

摘要:

Experimental results are presented regarding the switching of a bistable semiconductor laser’s output (PO) with injected optical power (PI). An incident optical beam, generated by an ordinary semiconductor laser, was injected into the bistable semiconductor laser with inhomogeneous excitation. The mutual relation betweenPI‐POcharacteristics andI‐Lcharacteristics for the bistable laser, and the dependence ofPI‐POcharacteristics on the bias current of the bistable laser are described. Switching between the two stable bistable operation states is accomplished by injecting optical trigger pulses. Switching of the laser having differential gain characteristics, through use of optical pulse, is also looked at.

ISSN:0003-6951    

DOI:10.1063/1.93640

出版商:AIP    

年代:1982

数据来源: AIP