摘要:

Metal/metal oxide and metal/metal nitride thin‐film composites (metal=In,Cu) have been prepared by reactive ion beam sputter deposition (RIBSD) and incorporated into antireflection trilayer structures. The RIBSD technique produces thin, homogeneous films whose complex index of refraction can be reproducibly varied. We find the In/InOxcomposite to have extremely favorable characteristics for optical recording, such as an optimized 0.25‐nJ threshold sensitivity, a reflection contrast ratio higher than 60, and good environmental stability. Repeated write‐erase cycles have demonstrated a fast reversible phase change which occurs without noticeable degradation in reflection contrast.

ISSN:0003-6951    

DOI:10.1063/1.94631

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Brillouin component is observed for the first time along the backscatteredmlines in the anisotropic film waveguides. Each order of the forward as well as the backscatteredmlines is found to be split into two components and are attributed to the presence of TE and TM modes. Temperature conditions under which the films are made and the thickness of the films are found to be critical. Polystyrene films are used in the investigations as waveguide materials due to their compatibility.

ISSN:0003-6951    

DOI:10.1063/1.94632

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We report a new Al0.48In0.52As/Ga0.47In0.53As avalanche photodiode with separate absorption and multiplication regions (SAM APD) and an undoped spacer layer in the gain region. These devices grown by molecular beam epitaxy, have very low dark currents (4 nA at the onset of gain) which compare favorably with state‐of‐the‐art InP/Ga0.47In0.53As SAM APD’s. Avalanche gains ≊60 and a high speed of response with a gain‐bandwidth product ≊10 GHz are demonstrated. Receiver sensitivity measurements at 420 Mb/s and &lgr;=1.3 &mgr;m with a Si bipolar transistor preamplifier yielded −36.0 dBm at a 10−9bit error rate.

ISSN:0003-6951    

DOI:10.1063/1.94633

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The newly developed differential carrier lifetime and threshold carrier density measurement techniques are applied to temperature‐dependent measurements of the recombination rates and threshold carrier density of III‐V semiconductor lasers. Quantities obtained from these measurements are used to predict the temperature dependenceT0of the threshold current, which is in excellent agreement withT0observed at 20 °C for both InGaAsP and AlGaAs lasers. The main causes for the stronger temperature sensitivity of InGaAsP material are due to Auger recombination and a smaller radiative coefficient.

ISSN:0003-6951    

DOI:10.1063/1.94634

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The first measurements of infrared birefringence of liquid crystals are reported. Continuous birefringence spectral data were calculated from measurements of phase differences which occur when monochromatic polarized light propagates through a medium with an anisotropic refractive index. It was found that molecular absorption bands can provide significant resonant enhancement of the refractive indices of liquid crystals, and this effect causes the birefringence of these materials to be relatively large throughout the spectral region from 2 to 16 &mgr;m. The birefringence and absorption spectra of two particular liquid crystal mixtures indicate that liquid crystals will be useful for electro‐optic applications in the infrared region.

ISSN:0003-6951    

DOI:10.1063/1.94635

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

InGaAsP/InGaP lasers emitting at 724–727 nm have been fabricated on GaAs substrates using liquid phase epitaxy. The threshold current is reduced to 8 kA/cm2by thinning the active layer. Room‐temperature cw operation is achieved for the first time in the lasing wavelength range below 760 nm in this quaternary system.

ISSN:0003-6951    

DOI:10.1063/1.94628

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Single crystals of undoped and cerium‐doped yttrium aluminum garnet have been pumped with laser radiation of 220‐ and 266‐nm wavelength. A broadband defect emission at approximately 300 nm was observed, similar to that obtained with cathodoluminescence, although decreased in magnitude. Evidence of a transfer of energy from these defect states to the Ce+3states was inferred from the photoluminescence decay time measurements. We have associated the absorption spectra from 200–300 nm with the defect excitation spectrum, including the peaks at 225 and 270 nm.

ISSN:0003-6951    

DOI:10.1063/1.94629

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Previous experiments have shown that very high etch rates can be obtained with an rf hollow cathode reactive sputter etching apparatus. This letter shows that hollow cathode etching also permits profile control, without mask undercut or mask erosion. The angle of etching is here varied from 90° (i.e., normal to the etched surface) to 50°, at a constant pressure of CF4and a constant applied rf voltage, by varying the etch conditions. The etch angle is largely independent of the etched material (SiO2or Si).

ISSN:0003-6951    

DOI:10.1063/1.94630

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Amorphous alloys have been produced by Ar+beam irradiation of Au‐Ge thin‐film bilayers. Two different average compositions have been detected for implantation at 80 or at 300 K, respectively. Each amorphous phase decomposes into a crystalline one after aging at room temperature for several hours. The composition and structure of such crystalline phases are also controlled by the irradiation temperature. Prolonged annealing at 45 °C produces precipitation of pure Au and Ge respectively. The metastable crystalline phase formed at LN2T irradiation is tetragonal and has a composition range close to the &khgr; phase formed after splat cooling technique. The room temperature phase has instead an hexagonal structure.

ISSN:0003-6951    

DOI:10.1063/1.94636

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Heteroepitaxial films of CdTe and HgCdTe have been grown on InSb and GaAs substrates by metalorganic chemical vapor deposition. The CdTe growth temperature was 440 °C and the HgCdTe growth temperature was 410 °C. Specular CdTe films were obtained on (110) and (211) InSb substrates and (100) GaAs substrates. Specular surfaces of HgCdTe/CdTe/InSb and HgCdTe/CdTe/GaAs heterostructures were also obtained. X‐ray diffraction measurements indicated that the heteroepitaxial films were single crystalline. The growth plane of the CdTe films on InSb substrates was slightly misoriented from the InSb orientation. The heteroepitaxial films deposited on GaAs substrates replicated the substrate orientation.

ISSN:0003-6951    

DOI:10.1063/1.94637

出版商:AIP    

年代:1984

数据来源: AIP