摘要:

A phased array with an integrated phase shifter which can convert a 180° phase mode into an in‐phase mode was demonstrated. An Al2O3facet coating with a different thickness on each array element was performed. It should act as the phase shifter. A stable single‐lobed far‐field pattern was obtained from the array with the phase shifter.

ISSN:0003-6951    

DOI:10.1063/1.97773

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Spectroscopic ellipsometry studies (1.66–5.5 eV) of Cu‐Ni thin films, containing short (0.62 and 4.13 nm) lattice‐commensurate modulation wavelengths, have revealed a strong anisotropy of the dielectric function. These observations are discussed, in accordance with theoretical predictions for superlattices, in terms of the coherency strains. Other possible sources of anisotropy are also discussed in conjunction with other studies.

ISSN:0003-6951    

DOI:10.1063/1.97774

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

A technique using a new external cavity structure to cause degeneration at the frequencies of two orthogonally polarized modes and to control the polarization and the frequency in a semiconductor laser has been devised. The phase difference between the polarizations in the gain medium can be canceled in a round trip through quarter‐wave plates set in the cavity. By rotating one of the quarter‐wave plates, orthogonally polarized laser beams can theoretically be made to oscillate at slightly different frequencies. Experimentally, two orthogonally polarized oscillations with rather large frequency differences occurred. The difference between the two frequencies alternated according to the quarter‐wave plate rotation. This phenomenon could be explained theoretically.

ISSN:0003-6951    

DOI:10.1063/1.97775

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Stable in‐phase coupled supermode operation of a ridge waveguide laser array is achieved by introducing distributed saturable absorption regions in subordinate laser cavities. Diffraction‐limited single‐lobed emission beams were attained up to 27 mW per laser stripe, and threshold current for the array was kept near 10 mA per laser stripe.

ISSN:0003-6951    

DOI:10.1063/1.97776

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Laser emission at 2.8 &mgr;m from an Er3+:LiYF4sample longitudinally pumped with a multiple stripe laser diode array is observed for the first time. The threshold for pulsed laser emission is 33 &mgr;J and for cw laser emission 147 mW. cw laser action in this normally self‐terminating laser transition is attributed to a cooperative up‐conversion process.

ISSN:0003-6951    

DOI:10.1063/1.97777

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Stationary cavities were formed in liquids by trains of laser pulses having the following characteristics: high absorption, high repetition rate, and high energy per pulse. Under these conditions laser pulses may be transmitted through several millimeters of ‘‘opaque’’ liquids by a cavitation effect. This facilitates material cutting and laser surgical operation under blood or under water by CO2or excimer lasers. A simple model is presented to explain the cavitation effect.

ISSN:0003-6951    

DOI:10.1063/1.97778

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Nonlinear Fabry–Perot e´talons of GaAs have been fabricated with metalorganic vapor phase epitaxy technology. The e´talons operate in reflection mode, and have an epitaxially grown, rear dielectric mirror consisting of a stack of alternating AlAs/GaAlAs layers. Optical logic functions using a HeNe laser and optical bistability at room temperature are reported. Low switching powers and improved e´talon uniformity are obtained.

ISSN:0003-6951    

DOI:10.1063/1.97779

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The evolution of an optical field along a symmetrical slab waveguide capable of supporting two TE modes in the linear regime is investigated using the beam propagation method (BPM) where the waveguide and cladding media have a uniform, self‐focusing Kerr law nonlinearity. BPM calculations agree well with coupled‐mode theory at low input powers, but diverge at powers approaching the coupled‐mode value of the critical power and above, due to self‐focusing of the field. At high power, the beam splits into two parts which generate unusual long‐range collision effects.

ISSN:0003-6951    

DOI:10.1063/1.97780

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

It is reported for the first time that refractive indices are reduced remarkably by residual stress in undoped silica‐core/fluorine‐doped silica‐clad single‐mode fibers. The very high residual stress concentrated at the small diameter core is induced by drawing tension because of the difference in viscosity between the core and cladding. The decrease in refractive indices results from photoelastic effects due to residual stress in the core.

ISSN:0003-6951    

DOI:10.1063/1.97781

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

We describe a high‐power extended‐cavity laser which uses a multiple transverse mode laser as the gain medium and an intracavity single‐mode fiber for mode stabilization. The laser delivers up to 30 mW to a single‐mode fiber.

ISSN:0003-6951    

DOI:10.1063/1.97782

出版商:AIP    

年代:1987

数据来源: AIP