摘要:

Active mode locking of a UV preionized transverse discharge XeCl laser has been achieved by modulating the gain using an intracavity Pockel’s cell. The output was 100% modulated, and pulses as short as ∼310 ps were measured. Generation of shorter pulses by the same method is discussed briefly.

ISSN:0003-6951    

DOI:10.1063/1.92656

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We report the first demonstration of a polarization‐independent, integrated‐optic wavelength filter. Polarization‐independent filtering is achieved via wavelength selective TE↔TM conversion between a pair of mismatched Ti‐diffused lithium niobate waveguides. A peak coupling efficiency of ∼75% and 5‐A˚ filter bandwidth have been achieved.

ISSN:0003-6951    

DOI:10.1063/1.92657

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A heterostructure semiconductor laser with graded‐index waveguide and separate carrier and optical confinements prepared by molecular beam epitaxy is discussed. These lasers have very low broad‐area threshold current densitiesJth500 A/cm2and support narrow beams of Gaussian distribution with far‐field half‐power full‐width in the direction perpendicular to the junction plane &Vthgr;⊥∼20°–30°. It is also shown that only when the active layer thickness is ≲700 A˚ a significantly lowerJthis obtained by employing the symmetric laser structure instead of the regular double heterostructure.

ISSN:0003-6951    

DOI:10.1063/1.92658

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

An atomic iodine laser, a candidate for the direct solar‐pumped gas laser, was excited with a 4‐kW beam from a xenon arc solar simulator. Continuous lasing at 1.315 &mgr;m for over 10 ms was obtained for static filling ofn‐C3F7I vapor. By momentarily flowing the lasant, a 30‐Hz pulsed output was obtained for about 200 ms. The peak laser power observed was 4 W for which the system efficiency reached 0.1%. These results indicate that direct solar pumping of a gas laser for power conversion in space is indeed feasible.

ISSN:0003-6951    

DOI:10.1063/1.92659

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Direct nuclear pumping of a low‐temperature (≊150 K)3He‐CO laser has been achieved using the volumetric3He(n,p)3H nuclear reaction. Lasing occurred on the vibrational bands of CO at ≊5 &mgr;. Effects of N2on the system were investigated, as well as scaling of laser output with CO concentration, thermal neutron flux, and total pressure. This is the first volume‐pumped, nuclear powered CO laser.

ISSN:0003-6951    

DOI:10.1063/1.92660

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Intense photoexcitation of GaAs by picosecond laser pulses creates a superdense electron‐hole plasma (∼1020cm−3) which sustains laser action from 8900 A˚ in the IR to 7700 A˚ in the visible. Tunable picosecond laser pulses are obtained by moving a slightly wedged ultrashort cavity in the focus of the pump laser pulse.

ISSN:0003-6951    

DOI:10.1063/1.92661

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The effect of various rare‐gas diluents on the operating parameters of the XeCl laser has been investigated. The laser was electron‐beam pumped at an excitation rate of ≊3 MW/cm3and a pulse duration of 50 nsec. Contrary to previous results we found that the intrinsic efficiency, small‐signal gain, and absorption were independent of the rare‐gas diluent. The intrinsic efficiency was ≊ 4%, the small‐signal gain was 0.18 cm−1, and the absorption coefficient was between 0.04 and 0.05 cm−1. A saturation intensity of 3 MW/cm2was obtained from a modified Rigrod analysis of the data.

ISSN:0003-6951    

DOI:10.1063/1.92662

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Electron temperature measurements in highly ionized titanium plasmas are reported. The plasmas were created by imploding cylindrical arrays of fine wires with the Blackjack 5 pulse generator (Peak diode voltage≊3.0 MV, peak current≊4.6 MA, peak power ≊10 TW at full operating level). Temperatures between 0.7 and 2.3 keV were obtained from the slope of the free‐bound continuum. The results of these measurements are compared to temperature measurements obtained from the intensity ratio for the H‐like (1s–2p)/He‐like (1s2–1s3p1P) transitions. The line ratio method gave temperatures which ranged between 1.55 and 2.15 keV. Data are presented from eleven implosions at generator power levels between 5.2 and 7.5 TW.

ISSN:0003-6951    

DOI:10.1063/1.92641

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We report that continuous, incoherent light from a xenon arc lamp can be used to completely activate implanted Si (100) samples (75As+:100 keV, 1×1015cm−2) with negligible dopant redistribution and excellent uniformity (sheet resistivity variation less than ±2% over a 3‐in.‐diam wafer). An entire 3‐in. wafer could be activated in only about 10 sec without relative motion of wafer and light beam. The extent to which implant damage was removed by the incoherent light anneal is qualitatively indicated by the carrier mobilities which were within 10% of single‐crystal values.

ISSN:0003-6951    

DOI:10.1063/1.92642

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Simultaneous variations of the concentrations of As, Si, and H in As doped and undoped sputtereda‐Si:H structures are reported. The As is substitutional for Si, but most of the As atoms are also connected with an additional hydrogen and so inefficient for doping. The As doping also decreases significantly the material density. These results are shown to reject the usual assumption according to which doping atoms just supply carriers in the otherwise unchanged distribution of states of undopeda‐Si:H.

ISSN:0003-6951    

DOI:10.1063/1.92643

出版商:AIP    

年代:1981

数据来源: AIP