摘要:

A new technique for controlled etching of micrometer‐size regions on thin films has been developed. Dopant atoms are deposited on the film surface by UV laser photodissociation of a gas and incorporated by simultaneous heating with a visible laser beam. The process has been demonstrated by laser alloying Al films with Zn to produce localized chemically reactive regions of Zn/Al alloy.

ISSN:0003-6951    

DOI:10.1063/1.92394

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Absolute laser‐damage thresholds can be rapidly measured by comparison with an absolute laser‐damage standard. Multiple‐layer TiO2/SiO2antireflection films on BK‐7 glass were found to be the best available damage standards for use at 1064 nm.

ISSN:0003-6951    

DOI:10.1063/1.92395

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Collisional dissociation of I2by O2(1J) has been directly observed by monitoring the appearance rate and amplitude of transient I(52P3/2) absorption on the 62P3/2‐52P3/2resonance line at 178 nm. A pulsed, Raman‐shifted dye laser was used to excite a single rotational line of O2(1J,v′ = 0) near 763 nm. Radiation at this wavelength also dissociated some I2via absorption to the continuum region of the I2(A3R1u) state. The variation in the appearance rate of the iodine atom signal with I2pressure leads to a rate constant for total deactivation of O2(1J) by I2ofk= 7×10−11cm3 molecules−1 sec−1. Comparison of the amplitude of the I‐atom absorption signal induced by O2(1J) dissociation of I2to that resulting from direct I2photodissociation leads to the conclusion that the branching ratio for O2(1J)+I2→O2+2 I versus all other pathways is less than 0.2.

ISSN:0003-6951    

DOI:10.1063/1.92396

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

We have calculated the nonradiative Auger recombination rate as a function of temperature in InGaAsP. Inclusion of this process can explain the observed temperature dependence of threshold and carrier lifetime of both the 1.3‐ and 1.55‐mm InGaAsP double‐heterostructure lasers. The threshold calculations are carried out using the Halperin‐Lax‐Kane band model, Stern’s matrix element, and Beattie‐Landsberg theory of Auger recombination. Evidence of the Auger recombination is provided by a sublinearity of the spontaneous emission as a function of injection current.

ISSN:0003-6951    

DOI:10.1063/1.92380

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Experiments characterizing the temperature sensitivity of tapered‐gap prism coupling to in‐ and out‐diffused lithium niobate optical waveguides are reported. Reduction in coupling efficiency with changes in ambient temperature are shown to be related primarily to the temperature dependence of lithium niobate’s extraordinary refractive index. Optimum coupling efficiency is shown to be recoverable by adjustment of only the prism coupling angle. Several methods are discussed for dealing with this problem.

ISSN:0003-6951    

DOI:10.1063/1.92397

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Compensation for the first‐order temperature coefficient of phase delay (TCD) of GaAs surface acoustic wave delay lines has been experimentally achieved using a two‐layer Au/SiO2film coating. The negative TCD of SiO2provides temperature compensation, while the mass loading effect of the gold layer provides nonleaky Rayleigh wave propagation.

ISSN:0003-6951    

DOI:10.1063/1.92398

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

A new electrical breakdown effect is reported in which optical pulses are produced by applying an alternating field of low frequencyfA(1 Hz<fA< 600 Hz) to a gas‐filled glass bulb. The mean number of pulses in the periodf−1Adepends linearly on the field amplitude, and the minimum voltage required across the bulb diameter to maintain the effect satisfies Paschen’s law. In a typical case, a 25‐mm‐diam bulb filled with neon at a pressure of 1–10 Torr flashed at a frequency of 120 Hz when subjected to a 60 Hz field of 15 kV/m rms. The results are explained by a model in which each breakdown resets the field inside the bulb to zero, thereby quenching further optical emission until the next breakdown occurs.

ISSN:0003-6951    

DOI:10.1063/1.92399

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The results of implantation of various ions (Li,C,P,Ge, and Sb) into heated diamond (∼1000 °C) are studied by channeling techniques. The residual damage and the locations in the lattice, which the implants occupy, are determined. It is shown that by implanting into heated diamond (i) graphitization can be avoided and (ii) an appreciable fraction of Li ions can be driven into interstitial sites where they are expected to be electrically active donors.

ISSN:0003-6951    

DOI:10.1063/1.92400

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

Transparent, purec‐oriented ZnO films have been deposited on various substrates utilizing a magnetron sputter gun. The design of the gun and of the sputtering system helps to keep the substrate surface free from charged particle bombardment and excessive heat by radiation. The substrate temperature can be maintained as low as 98 °C reducing the effects of thermal stress to a minimum. A comparison is made between the conventional planar magnetron system and the sputter gun. The design of the sputter gun has overcome some of the difficulties which have existed in standard planar magnetron sputtering. Sputtering parameters and results are discussed as well as the advantages of using a reactively sputtered zinc target over a zinc‐oxide target.

ISSN:0003-6951    

DOI:10.1063/1.92381

出版商:AIP    

年代:1981

数据来源: AIP

摘要:

The high recrystallization velocities attained in the pulsed‐laser annealing of ion‐implanted semiconductors lead to remarkable nonequilibrium segregation effects. Detailed studies of these effects and the physical mechanisms which underlie them require control of the recrystallization velocity over a wide range. In this letter, the results of computer calculations are used to demonstrate three methods for controlling the regrowth velocity in Si and to indicate the range of velocities which may be expected by the methods.

ISSN:0003-6951    

DOI:10.1063/1.92382

出版商:AIP    

年代:1981

数据来源: AIP