摘要:

This paper reports the first direct application of a nitrogen laser as a frequency mixing component in a parametric experiment. Tunable infrared radiation from 0.68 to 1.1 &mgr;m is generated by mixing N2laser and dye laser pulses in ADP. The experimental tuning curve is in good agreement with theory. A peak signal power of 1 W is obtained over an interaction length of 1.1 cm with 7 kW of N2laser and 5 kW of dye laser power. The signal bandwidth is consistent with those of the input beams. Possible extensions of the tuning range are discussed.

ISSN:0003-6951    

DOI:10.1063/1.89334

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

We demonstrate the locking of an optically levitated sphere to an external reference using an electronic feedback system. This provides a new external source of damping for the stabilization and manipulation of particles in vacuum and at atmospheric pressure. The method permits accurate and continuous monitoring of applied forces. Numerous applications are suggested.

ISSN:0003-6951    

DOI:10.1063/1.89335

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Experimental results show that the peak velocity, peak electric field, and saturated velocity of the velocity–electric‐field curve forn‐GaAs all increase substantially with increasing hydrostatic pressure up to about 10 kbar; the peak velocity and field then begin decreasing with further increase in pressure. The extraction of the data from the current‐voltage characteristics is based on an exploitation of the influence of the boundary conditions on the manifestation of transferred‐electron‐induced (Gunn) current instabilities.

ISSN:0003-6951    

DOI:10.1063/1.89336

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Reported in this paper are the first experiments designed to separate the effects of reabsorbed recombination radiation (RRR) and diffusing minority carriers on the measured minority‐carrier diffusion length. From light spot scan experiments on bevelled samples ofp‐type Ge‐doped GaAs it was found that forp‐layer thicknesses up to two diffusion lengths (10–20 &mgr;m) carriers created by RRR represent less than 10% of the total carriers diffusing from a generating source (illumination ofp‐njunction injection). Thus for measurements and structures of interest carriers created by RRR play no substantial role.

ISSN:0003-6951    

DOI:10.1063/1.89337

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

Thin‐film PbTe photodiodes have been operated at 80 K with significantly reduced capacitance. The technique is based upon limitation of the voltage‐induced change of the depletion‐layer volume by the presence of an insulating substrate. Capacitances as low as 64 pF for a 9‐mil‐square diode and 35 pF for a 28‐mil‐square diode have been achieved with retention of background‐limited detectivities, which were typically about 1.7×1011cm Hz1/2 W−1for peak wavelength near 5 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.89338

出版商:AIP    

年代:1977

数据来源: AIP

摘要:

The advantages of exploiting the anisotropic &ggr; radiations from oriented nuclei in the development of grasers are pointed out. Nuclear orientation may be achieved by either static or dynamic means. Some simple techniques for switching the direction of nuclear polarization and hence of the radiation emission are summarized.

ISSN:0003-6951    

DOI:10.1063/1.89339

出版商:AIP    

年代:1977

数据来源: AIP