摘要:

We propose and demonstrate the first Ti:LiNbO3waveguide‐InGaAsP/InP composite cavity laser. Mode locked optical pulses shorter than 22 ps have been generated at repetition rates up to 7.2 GHz by sinusoidally driving the integrated traveling‐wave directional coupler switch.

ISSN:0003-6951    

DOI:10.1063/1.95451

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Significantly improved XeF(C→A) laser performance has been achieved using electron beam excitation of complex, multicomponent gas mixtures specifically tailored so as to reduce medium transient absorption in the blue‐green region. Use of Ar and Kr together as the effective rare gas buffer‐energy transfer species, along with a combination of NF3and F2to produce the desired F‐donor molecule characteristics, has permitted synthesis of near optimum medium properties for which XeF(C) is produced efficiently while transient absorption is minimized. With this technique we have achieved laser pulse energy density and intrinsic efficiency of 2.2±0.3 J/l and ∼1.5%, respectively, values that are comparable to those of theB→Xrare gas‐halide lasers.

ISSN:0003-6951    

DOI:10.1063/1.95452

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We calculate the relaxation oscillation corner frequencyfrand the linewidth enhancement factor &agr; for both a quantum well and a quantum wire semiconductor laser. A comparison of the results to those of a conventional double heterostructure device indicates thatfrcan be enhanced by 2× in the quantum well case and 3× in the quantum wire case while &agr; is reduced in both cases.

ISSN:0003-6951    

DOI:10.1063/1.95453

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The phase and the amplitude of the photoacoustic signal are measured as a function of chopping frequency for a thin polyester film, using two different backing materials (water and ethanol). Analysis of the results shows agreement with Rosencwaig–Gersho theory [J. Appl. Phys.47, 64 (1976)] and provides values of the thermal diffusivity and the thermal effusivity of the sample.

ISSN:0003-6951    

DOI:10.1063/1.95454

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A method for the preparation of lamellae of Si and CoSi2using thin‐film eutectic solidification techniques is presented. In the experiment, a laser was used to melt and directionally solidify an alloyed film of Co and polycrystalline Si on a thermally oxidized Si wafer. Using traverse rates as rapid as 8 cm/s, 50‐nm‐wide CoSi2stripes, separated by comparable amounts of Si are obtained. An analysis of the chemistry and microstructure of the film before and after laser scanning is discussed.

ISSN:0003-6951    

DOI:10.1063/1.95455

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We demonstrate that an ion beam analysis method that detects the energies of forward recoiling deuterons can be used to measure concentration profiles and tracer diffusion coefficientsD* of a deuterated polymer (d‐polystyrene) diffusing into its hydrogenated analog. TheD*’s decrease asM−2as predicted by the reptation theory of polymer diffusion and agree in magnitude with both the theory and marker displacement measurements ofD* in the same system.

ISSN:0003-6951    

DOI:10.1063/1.95456

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We report a double insulated CaS:Ce thin‐film electroluminescent (EL) device which emits a bright green EL due to Ce3+luminescent centers, being characteristic of parity allowed 5d–4ftransitions. A brightness level of 500 cd/m2and emission efficiency of 0.11 lm/W have been obtained under 5‐kHz sinusoidal voltage excitation. The CaS:Ce thin film has been fabricated by coevaporation of CaS and sulfur.

ISSN:0003-6951    

DOI:10.1063/1.95457

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

High resolution photoluminescence spectroscopy at 4.2 K and at a magnetic field of 9.7 T is employed to resolve and identify residual shallow donors in liquid phase epitaxial InP. Sulphur is found to be the dominant inadvertent contaminant in high purity material prepared from growth solutions which have undergone long baking treatments. Silicon is also observed in most samples, but at significantly lower levels than sulphur.

ISSN:0003-6951    

DOI:10.1063/1.95458

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Yellow‐emitting pulsed laser operation of an Al0.37Ga0.15In0.48P/Al0.16Ga0.36In0.48P/ Al0.37Ga0.15In0.48P double heterostructure laser diode was obtained at 77 K. The emission wavelength was 579 nm. The threshold current density was 5.6 kA/cm2for a diode with a Si3N4insulated 8‐&mgr;m‐wide and 250‐&mgr;m‐long stripe geometry. The device was made from a DH wafer grown by conventional metalorganic chemical vapor deposition using triethyl metals and phosphine as source materials.

ISSN:0003-6951    

DOI:10.1063/1.95459

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Silicon direct nitridation has been successfully done using purified ammonia gas and an ArF excimer laser (&lgr;=193 nm). Direct nitride films were grown at a substrate temperature of 400 °C and a laser pulse energy of 15 mJ/pulse cm2. As far as Auger signal intensities are concerned, there is little difference between the excimer laser enhanced nitrided films grown at 400 °C and thermally nitrided films grown at 1000 °C. The maximum film thickness grown is limited to 2.5 nm at 400 °C by diffusion of nitridation species across the grown film. The temperature rise on the substrate surface irradiated by the laser was calculated and found to be around 50 °C. Therefore, the thermal effect of the laser irradiation is of little significance in this experiment. The photochemically dissociated products of ammonia molecules were investigated by a quadrupole mass analyzer. The photochemically generated NH2radicals seem to enhance the nitridation.

ISSN:0003-6951    

DOI:10.1063/1.95466

出版商:AIP    

年代:1984

数据来源: AIP