摘要:

Nonlinear optical cavities are known to exhibit bistability and multistability. In this letter the properties of microwave Fabry–Perot and ring resonators with second‐order dispersive nonlinearity are analyzed. Experimental results such as multiple‐valued output versus input characteristics, resonance curves, and waveforms are described. On the basis of harmonic and subharmonic generation a new mechanism is found leading to multistability, which is quantitatively attributed to well‐defined soliton modes propagating in the resonator.

ISSN:0003-6951    

DOI:10.1063/1.94658

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The temperature dependence of the photoelectron polarization is identical for GaAs with positive and negative electron affinity, as well as for Ge. It is concluded that the depolarization is due to a surface effect.

ISSN:0003-6951    

DOI:10.1063/1.94659

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The effects of active layer thickness on the astigmatism, the angle of far‐field pattern width parallel to the junction, and the spectral envelope width of a gain guided laser with a narrow stripe geometry have been investigated analytically and experimentally. It is concluded that a large level of astigmatism, a narrow far‐field pattern width, and a rapid convergence of the spectral envelope width are inherent to the gain guided lasers with thin active layers.

ISSN:0003-6951    

DOI:10.1063/1.94660

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Emission spectra in the visible and ultraviolet range, and scanning electron microscopy of polyimide films exposed to 193, 248, and 351‐nm laser radiation were used to elucidate the mechanism of the laser etching process. It was found that rough laser etched surfaces, with nonuniformities larger than 0.5 &mgr;m, are accompanied by a continuum emission from the blow‐off materials, while smooth surfaces are characterized by strong C2emission in theA 3&Pgr;g→X′ 3&Pgr;&mgr;bands. Smoothly etched surfaces were obtained for all laser wavelengths provided the energy absorbed per unit volume in the surface exceeds a threshold value of (5.0±0.5)×104J/cm3. It is suggested that surface smoothness results from transient melting and that the laser etching mechanism is mostly a statistical thermodynamic process without complete energy randomization.

ISSN:0003-6951    

DOI:10.1063/1.94661

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

At frequencies near 1 GHz, the acoustic wavelength in argon gas becomes half that of visible light, making possible collinear Bragg scattering of laser light by the sound. This acousto‐optic interaction has been used to detect photothermally generated acoustic power at the surface of solids. This new technique provides a noncontacting probe for the detection of 100–1000‐A˚ thermal waves with optical resolution. The essential features of the theory behind this new photothermal probe are presented along with a description of the experimental implementation. High resolution images of implanted silicon are included which clearly demonstrate the sensitivity of the probe to variations in the thermal characteristics of solids.

ISSN:0003-6951    

DOI:10.1063/1.94662

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A simple technique has been developed for the fabrication of lead‐salt cleaved‐coupled‐cavity diode lasers. The improvement in spectral purity and the reduction in threshold current of these coupled‐cavity lasers will be discussed.

ISSN:0003-6951    

DOI:10.1063/1.94663

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Nine distinct rotational laser lines of the ([10° 1]I–[10° 0]I) vibrational band of13C 16O2near 4 &mgr;m have been observed and identified. Wavelength measurements of these lines are given as well as a simplified design for a CO2cascade laser resonator.

ISSN:0003-6951    

DOI:10.1063/1.94664

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Based on the author’s earlier work, it is shown that the proper inclusion of carrier scattering should strongly modify the frequency and polarization dependence of optical nonlinearities due to mobile carriers in semiconductors. When the momentum relaxation is much faster than the energy relaxation, the intensity dependent refractive index is enhanced, the induced birefringence becomes a sharp function of the difference frequency &ohgr;a−&ohgr;b, and a collision induced stimulated Raman effect becomes important.

ISSN:0003-6951    

DOI:10.1063/1.94655

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Fifteen recombination lasers have been produced in the ionic species of nine elements by focusing eight transversely excited atmospheric pressure CO2laser beams onto targets of these materials to produce an elongated gain region in the vaporized plasmas. The results include the first lasers in ionized species and also the first visible lasers excited by this process.

ISSN:0003-6951    

DOI:10.1063/1.94656

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The theory of the spectral linewidth of a single longitudinal laser mode is re‐examined on the basis of a phase diffusion model. The contribution to the linewidth resulting from the coupling of phase and amplitude (self‐coupling term described by the enhancement factor &agr;) is investigated exactly. In particular, the commonly used approximation of a small spontaneous emission rate and/or strongly damped relaxation resonance is not applied. The self‐coupling then results no longer in a constant enhanced slope in the Schawlow‐Townes formula. The enhancement linewidth itself is now no linear function of the inverse optical power and decreases to zero in the limit of high spontaneous emission rates and small optical power. Therefore, deviations from the linear dependence of the mode linewidth on mode power are predicted.

ISSN:0003-6951    

DOI:10.1063/1.94657

出版商:AIP    

年代:1984

数据来源: AIP