摘要:

First order distributed feedback laser with periods down to 94 nm based on ZnSe have been realized by electron beam lithography and wet chemical etching. Distributed feedback operation was demonstrated by optical excitation using a pulsed N2laser. A threshold density of 80 kW/cm2was found at room temperature for a resonator length of 225 &mgr;m. From the stop band width, a coupling coefficient of 120 cm−1can be estimated. By varying the grating period the emission wavelength can be tuned over a wide spectral range of more than 130 meV. Measurements in the range between 20 and 300 K show that the shift of the emission wavelength with temperature is reduced by more than a factor of four as compared to the temperature shift of the spontaneous emission. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115478

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Lasing threshold modes are studied experimentally for microcavity lasers fabricated to operate either as planar cavities, in which the mode is established by the emitter distribution, or as index‐guided modes in the planar cavity with weak three‐dimensional confinement. For no lateral index guiding, the lasing mode area is suggested to depend on the gain saturation. For lateral index confinement to a small area, spectral and radiation pattern measurements show that the spontaneous emission coupling is increased, and reduces the lasing threshold even in the presence of an increased loss. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115489

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Emission of bright (over 9 cd/m2) violet light centered at 404 nm has been achieved from SrS:Eu thin‐film electroluminescent (EL) devices. The brightness has remained stable after several hours of operation. The source of this light is believed to be the 5d–4ftransition of Eu2+in the SrCl2host, which is formed near the ZnS/SrS interfaces within the sandwich structure of the EL devices. Similar device structures were also utilized to produce ultraviolet EL emission at 367 nm from SrCl2:Ce3+layers. These devices were grown via atomic layer epitaxy. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115514

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Dramatic enhancement of the response rate of internal reflection self‐pumped phase conjugators with Ce‐ and Mn‐doped (K0.5Na0.5)0.2(Sr0.75Ba0.25)0.9Nb2O6crystals is observed with an intermittent laser beam as the pumping beam. Analysis that involves charge carrier migration driven by a photoinduced electric field is given. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115499

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We measured, through nearly degenerate three‐wave mixing, the third‐order nonlinear optical susceptibility of semiconductor doped glasses at frequencies below band gap. With typical 1.5%–5% volume fractions, the CdTe and CdS1−xSexnanocrystals give a contribution to the nonlinearity of the composite that is comparable to that of the glass matrix. The magnitude and the band‐gap dependence of the nonlinear susceptibility of the nanocrystals are similar to those of the bulk semiconductors. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115473

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Surface band structure and differential reflectance spectra of the (110)(1×1) surface of cubic silicon carbide crystals are investigated within a self‐consistent tight binding theory. The surface electronic band structure is characterized by the pronounced surface states in the gap and show metallic character. Optical transitions between the surface states cause an enormous reflectivity within the range of 1.0 to 1.5 eV and reveal strong polarization anisotropy. Influence of the atomic geometry of the (110)(1×1) surface on the differential reflectance of 3CSiC is studied. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115476

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We report an additive‐pulse mode‐locked (APM) thulium‐doped fiber ring laser producing 350–500 fs pulses tunable from 1798 to 1902 nm. The laser operates in the soliton regime, where periodic perturbations cause predictable sidebands and modulation in the optical spectrum. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115477

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Background limited infrared photodetection has been achieved up to 100 K at normal incidence withp‐type GaAs/Ga0.71In0.29As0.39P0.61quantum well intersubband photodetectors grown by low‐pressure metalorganic chemical vapor deposition. Photoresponse covers the wavelength range from 2.5 &mgr;m up to 7 &mgr;m. The device shows photovoltaic response, the cutoff wavelength increases slightly with bias, and the responsivity increases nonlinearly with bias. These effects are attributed to an asymmetric quantum well profile. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115479

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We report the recent measurement and analysis of the transmitted and pseudoreflected optically induced terahertz (THz) beams emitted from a semiconductor wafer under femtosecond laser illumination, where the static electric field is either parallel or perpendicular to the surface. In general, the amplitude of the transmitted THz field is different from that of pseudoreflected THz field, except at the Brewster angle. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115480

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A novel interferometer capable of measuring differential amplitude and phase with a single probe beam is presented. Differentiation in any direction can be performed in the detector plane which allows the system transfer function to be modified without altering the optical configuration. Differential amplitude and phase results are given for different detector arrangements and compared with theoretical predictions showing excellent agreement. ©1995 American Institute of Physics.

ISSN:0003-6951    

DOI:10.1063/1.115481

出版商:AIP    

年代:1995

数据来源: AIP