摘要:

A monolithic array of five noninteracting buried crescent lasers has been optically multiplexed using an external cavity with a grating as a dispersive element. The lasers have a center to center separation of 8 &mgr;m, and with an external cavity consisting of a 4‐mm focal length lens and a 600‐line/mm grating used in second order, the lasers emit at ≊1.31 &mgr;m in essentially single longitudinal modes separated by 19.6 A˚. Single longitudinal mode operation has also been obtained using a cleaved coupled cavity (C3) laser array. In this case the dominant mode is determined by the coherent interference of the mode spectrum of the two subcavities.

ISSN:0003-6951    

DOI:10.1063/1.94394

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

A low‐temperature mass transport process in InP was investigated. Mass transport of InP was achieved at 570–600 °C in a closed ampoule using iodine or InI as a catalytic transporting agent. Accomplishing the mass transport process at lower temperature has eliminated the problem of thermal etching and resulted in lasers with higherT0.

ISSN:0003-6951    

DOI:10.1063/1.94395

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Conjugated molecules, with large optical nonlinearities, are tested as materials usable for femtosecond optical Kerr shutter technique. With &bgr;‐carotene, in acetone solution, we have achieved responses limited by the 100‐fs width of the optical pulses and characterized by a resolution better than 1 ps with a dynamic range of 100.

ISSN:0003-6951    

DOI:10.1063/1.94396

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

We report tunable cw mode‐locked laser action from synchronously pumped HgCdTe lasers. 4–8‐&mgr;m‐thick liquid phase expitaxial layers lasing at &lgr;=1.2 and &lgr;=1.73–2.0 &mgr;m are longitudinally pumped by a neodymium: yttrium aluminum garret (Nd:YAG) laser. Peak output powers of 50 W using a chopped pump beam, and a cw mode‐locked average output power of 5.6 mW, have been achieved at a wavelength of 1.2 &mgr;m. Nearly bandwidth‐limited pulses of 6‐ps duration have also been obtained. Tuning from &lgr;=1.82 to 2.0 &mgr;m via the Burstein–Moss shift has been accomplished on a single epilayer by varying the loss in the external cavity.

ISSN:0003-6951    

DOI:10.1063/1.94397

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Investigation of phase noise in semiconductor lasers allows one to understand the physical processes that influence both the width and the shape of the emission line. Furthermore, the limitations associated with phase noise have to be taken into account when semiconductor lasers are employed in coherent optical communication systems. In this letter we report phase‐noise measurements on single‐mode semiconductor lasers in the presence of optical feedback. We are able to observe, besides the expected linewidth reduction, a peculiar behavior in the high‐frequency region not yet reported in the literature, strongly dependent on the external cavity length.

ISSN:0003-6951    

DOI:10.1063/1.94398

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

The weld penetration of a multikilowatt CO2laser has been increased by reducing the laser beam divergence. This near diffraction limited laser has now demonstrated that CO2lasers are capable of full‐penetration welding of 1‐in. steel with typically 11 kW on the work. Bead‐on‐plate tests combined with previous data indicate that the penetration scales with laser power asP0.8.

ISSN:0003-6951    

DOI:10.1063/1.94371

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Allowed transitions between then=1, 2, and 3 subbands of the conduction and valence bands of a multiple quantum well heterostructure of GaAs‐Al0.6Ga0.4As are seen in spontaneous emission under high excitations. The observed peaks agree very well with the calculated locations of the peaks when the finite depth of the potential well and the nonparabolicity of the conduction band are taken into account. The same basic features are seen under cw or picosecond pulse excitation and at room temperature, 77 K, or 4.2 K.

ISSN:0003-6951    

DOI:10.1063/1.94372

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

Stimulated emission on theB→Xband of CdI and isotopically enriched (98.6%)114CdI has been observed in a UV‐preionized, transverse discharge device with a gain length of 50 cm. For natural CdI, the laser energy is distributed among several transitions between 656 and 658 nm. The isotopically enriched114CdI spectrum, in contrast, is dominated by a single line at 657.1 nm, which contains >50% of the output energy. With a high‐Qoptical cavity, output energies >10 &mgr;J have been measured in a 85‐ns full width at half‐maximum (FWHM) pulse.

ISSN:0003-6951    

DOI:10.1063/1.94373

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

The mutual coherence of two coupled semiconductor lasers is investigated experimentally. It is demonstrated that by varying the gain in the overlap region, the degree of phase coherence can be continuously controlled. The quantitative characterization of the degree of phase coherence by fringe visibility is demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.94374

出版商:AIP    

年代:1983

数据来源: AIP

摘要:

An integrated optical chirped grating lens has been produced which exhibits high throughput efficiency (75%) and large angular field of view (3°). The waveguide substrate isx‐cut lithium niobate, and ion exchange in benzoic acid is the method used for making the lens and the waveguide.

ISSN:0003-6951    

DOI:10.1063/1.94375

出版商:AIP    

年代:1983

数据来源: AIP