摘要:

We measure the spectral characteristics of an external cavity semiconductor laser which uses a phase conjugate mirror for its external reflection. This device has significant advantages over the conventional external cavity system owing to the self‐aligning nature of the phase conjugate mirror. The fiber delay line self‐heterodyne technique is used to measure the fundamental linewidth for single mode operation of this device. It shows the linewidth to be at least as narrow as the instrumental resolution of 100 kHz.

ISSN:0003-6951    

DOI:10.1063/1.97280

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Durable electrochromic coatings of hydrated nickel oxide were produced by reactive rf magnetron sputtering of Ni followed by treatment in KOH. Spectrophotometry was used to assess the achievable modulation of luminous and solar transmittance and to verify that the studied material is interesting for ‘‘smart window’’ applications.15N nuclear reaction analysis suggested that coloration occurred upon hydrogen extraction.

ISSN:0003-6951    

DOI:10.1063/1.97281

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Time‐dependent electron density measurements of electron beam pumped XeCl laser mixtures (nonlasing) are performed using a CO2(10.6 &mgr;m) quadrature interferometer. The electron beam pulse length is ≊500 ns (full width at half‐maximum) and delivers ≳10 A/cm2at the foil. Electron densities are measured as a function of the halogen (HCl) and xenon concentration. For a 99.3% Ne/1.5% Xe/0.16% HCl mixture at 3000 Torr, the electron density peaks near the beginning of the pulse at ≊7×1014cm−3, decreases to 3×1014cm−3, then gradually increases to ≊6×1014cm−3at the end of the pulse. As the initial halogen concentration is reduced, the electron density increases, rising dramatically near the end of the pulse. This increase in the electron density later in the pulse is accompanied by a decrease of the XeCl* sidelight fluorescence.

ISSN:0003-6951    

DOI:10.1063/1.97282

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Silicon impurity induced disordering has been used to fabricate lasers with reduced facet absorption (facet windows) exhibiting enhanced catastrophic facet damage levels over comparable nonwindow devices. Power levels of 1.2 W cw were obtained from uncoated output facet devices and 2.1 W cw were obtained for a device with a coated output facet. Evidence is presented that the window region formed by silicon diffusion is a low‐loss waveguide which confines the propagating wave, increasing the efficiency of the device.

ISSN:0003-6951    

DOI:10.1063/1.97283

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A monolithic four‐channel optical transmitter at 0.8 &mgr;m wavelength has been fabricated. This has been achieved by using AlGaAs/GaAs optoelectronic integrated circuit (OEIC) approach. The OEIC chip contains four transmitter channels and each channel is composed of a graded‐index waveguide separate‐confinement heterostructure single quantum well laser, a monitor photodiode, and a laser driver circuit. The characteristics have been shown to be very uniform over four channels and pulse modulation responses over 1 Gb/s have been achieved.

ISSN:0003-6951    

DOI:10.1063/1.97284

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Upconversion pumping has been demonstrated both experimentally and theoretically to be important in the 2.8‐&mgr;m4I11/2–4I13/2lasing transition in a CaF2(Er3+) system. A minimum pump threshold of only 2.8 J with a 1‐ms Xe lamp pulse has been achieved in CaF2rods containing 5 mol % of Er3+ions. A simple theory has been developed to show that upconversion pumping makes possible cw lasing between the4I11/2and4I13/2states even when the lifetime of the terminal4I13/2state is much longer than that of the upper4I11/2state. Semi‐cw lasing has been experimentally demonstrated by pumping with six ganged photographic flash bulbs fired in sequence, with each bulb having a duration of 15–20 ms. Lasing at 2.8 &mgr;m lasted for 80 ms, well beyond 10 and 20 ms lifetimes of the4I11/2and4I13/2states. The 2.8‐&mgr;m CaF2(Er3+) laser has also beenQswitched, using a 100‐nm thin graphite foil as a shutter.

ISSN:0003-6951    

DOI:10.1063/1.97285

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

The influence of a bias electric field on the phase velocity of acoustic layer modes propagating along a ZnO overlay on a Si substrate is analyzed. Measurements of the fractional change in phase velocity as a function of the applied electric field were performed on both Rayleigh and Sezawa modes. The strength of the electroelastic effect has been experimentally determined for two samples obtained by different sputtering runs. An evident dependence of this parameter on the acoustic mode and on the quality of the sputtered film was observed. The maximum value of 15.8×10−6&mgr;m/V was attained by the Sezawa wave in one of the specimens, while a weaker effect was observed in the other cases.

ISSN:0003-6951    

DOI:10.1063/1.97286

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A finely focused ion beam is scanned over a surface on which a local gas ambient of dimethyl gold hexafluoro acetylacetonate is created by a directed miniature nozzle. The incident ions induce the selective deposition of gold along the path traced by the beam. The 15‐keV Ga+ion beam current is 100 pA and the beam diameter is 0.5 &mgr;m. Gold lines of 0.5 &mgr;m width and Gaussian profile are written. The film growth rate corresponds to five atoms deposited per incident ion. The focused ion beam deposited films contained 15% Ga, but less than 5% of other impurities, such as O or C. Deposition was also observed with broad ion beams of 750 eV Ar+and 50 keV Si+. The resistivity of the films varied from 2×10−5to 1.3×10−3&OHgr; cm.

ISSN:0003-6951    

DOI:10.1063/1.97287

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

A new high‐resolution profilometer has been demonstrated based upon a noncontacting near‐field thermal probe. The thermal probe consists of a thermocouple sensor with dimensions approaching 100 nm. Profiling is achieved by scanning the heated sensor above but close to the surface of a solid. The conduction of heat between tip and sample via the air provides a means for maintaining the sample spacing constant during the lateral scan. The large difference in thermal properties between air and solids makes the profiling technique essentially independent of the material properties of the solid. Noncontact profiling of resist and metal films has shown a lateral resolution of 100 nm and a depth solution of 3 nm. The basic theory of the new probe is described and the results presented.

ISSN:0003-6951    

DOI:10.1063/1.97288

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

This letter describes x‐ray precession photographs of (1,1,1) CdTe epitaxial layers on GaAs, CdTe, and Cd0.96Zn0.04Te substrates. The precession method is further applied to some (1,1,1) Hg1−xXxTe/CdTe superlattices whereX=Cd or Mn. More than half of the samples used in this study were grown by molecular beam epitaxy, others by metalorganic chemical vapor deposition, and a few by liquid phase epitaxy. The results unambiguously show that the common (1,1,1) face centered cubic twin fault, or stacking disorder, seen in bulk growth methods also exhibits its effects with the mentioned layer deposition growth techniques, except when liquid phase epitaxy is used. It seems that the twinning is intrinsic to the (1,1,1) growth in face centered cubic systems. In addition, devices with twin domains may have lower electronic mobilities. It further means that more experimental work is needed to produce untwinned single‐crystal materials deposited by molecular beam techniques.

ISSN:0003-6951    

DOI:10.1063/1.97289

出版商:AIP    

年代:1986

数据来源: AIP