摘要:

A newQswitching method for a semiconductor laser is proposed that uses an intracavity phase modulation due to the electro‐optic effect. It consists of an amplifier and two phase modulators driven by a microwave signal in a branching waveguide structure. It is predicted that underQswitching a pulse width of less than 100 ps with an intense peak power of a few watts is obtainable even with dc injection current slightly larger than the threshold by applying a microwave reverse bias voltage to the phase modulators.

ISSN:0003-6951    

DOI:10.1063/1.94843

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We report the observation of cw transverse optical bistability without power hysteresis at 1‐mW power levels in uncoated cadmium sulfide platelets. Optically induced refractive index changes as large as 0.15 are deduced from measurements of the transverse spatial ring profile.

ISSN:0003-6951    

DOI:10.1063/1.94844

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Tunable, cw, far‐infrared radiation has been generated by nonlinear mixing of radiation from two CO2lasers in a metal‐insulator‐metal (MIM) diode. The FIR difference‐frequency power radiated from the MIM diode antenna to a calibrated indium antimonide bolometer. Two‐tenths of a microwatt of FIR power was generated by 250 mW from each of the CO2lasers. The combination of lines from a waveguide CO2laser, with its larger tuning range, with lines from CO2, N2O, and CO2isotope lasers promises complete coverage of the entire far‐infrared band from 100 to 5000 GHz (3–200 cm−1) with stepwise‐tunable cw radiation. To demonstrate the usefulness of the technique, we observed theJ=4–5 line of CO at 567 GHz.

ISSN:0003-6951    

DOI:10.1063/1.94845

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We report the first measurement of the temperature dependence of the relative threshold carrier density,Nth, in InGaAsP‐InP lasers. The characteristic temperatureT′0, defined by 1/T0≡d ln Nth/dT, which is independent of nonradiative recombination mechanisms, is determined by transient pumping of a simple double heterostructure laser with optical pulses short (&bartil;100 ps) compared to the carrier lifetime (2–3 ns). A singleT′0as large as 120 K describes an exponential threshold dependence on temperature over a wide temperature range (160–370 K). Comparison with steady state (300 ns) excitation of the same samples shows that nonradiative recombination is responsible for the commonly observed injection laser break from a low‐temperatureT0&bartil;100 K to the poorer room‐temperatureT0&bartil;65 K. The measuredT0is smaller than a previously calculated value of approximately 200 K.

ISSN:0003-6951    

DOI:10.1063/1.94846

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We have demonstrated single photon detection (for &lgr;=1.3 &mgr;m) at a counting rate of 10 MHz. This is the highest photon counting rate ever achieved. We find that the quantum efficiency &eegr; is a weak function of the dark count rate ofrd, namely, &eegr;∝(rd)0.2. These results are encouraging for possible quantum limited lightwave receiver applications.

ISSN:0003-6951    

DOI:10.1063/1.94847

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

A passive compact TE‐TM mode splitter has been demonstrated using Ti:LiNbO3channel waveguides. Its operation is based on the interference between the two guided modes of a double‐mode waveguide segment connecting single‐mode input and output guides. A device made using one set of design parameters has splitting ratios of 12 dB for both polarizations. Another device made using different parameters has a splitting ratio of 17 dB for TM modes. The devices are capable of low‐loss, broadband operation.

ISSN:0003-6951    

DOI:10.1063/1.94848

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The first subnanosecond, time‐resolved, and spatially localized recombination continuum measurements are reported. The possibility of a non‐Maxwellian velocity distribution is deduced from the shape of the recombination spectrum that is observed during the time when the plasma is being created by the laser. The cooling rate of the plasma is derived for later times, when no laser heating is present.

ISSN:0003-6951    

DOI:10.1063/1.94835

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We have used an ultrahigh powered, 100‐kW vortex cooled arc lamp to anneal 75‐mm‐diam ⟨100⟩ silicon wafers implanted with various doses of 50‐keV B+and BF+2ions. Sheet resistivity measurements, secondary ion mass spectrometry, and transmission electron microscopy have been used to characterize the annealed wafers. Standard diffusion coefficients predict little dopant movement in the temperature (∼1200 °C) and time (∼1 s) region we studied. However, boron atoms which have been channeled relatively deep into the silicon and left in interstitial positions move ∼100 nm in ∼1 s at low temperatures, then stop. We presume that they encounter a vacancy and become substitutional. The dopant diffusion rate then is close to equilibrium values, and there is little measurable movement between 900 and 1250 °C. A 3‐s lamp cycle with maximum wafer temperature 1230 °C is sufficient to fully activate a 1014cm−2BF+2implant and leave the material with no extended defects. The dopant half‐width and junction depth are 50 and 250 nm for the as‐implanted sample, and 90 and 340 nm for the annealed sample.

ISSN:0003-6951    

DOI:10.1063/1.94836

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Plasma‐assisted epitaxy (PAE) has been applied to grow GaSb films at substrate temperatures as low as 340 °C. A hydrogen plasma can reduce the density of residual impurities and/or defects. The hole concentration and Hall mobility of an undoped GaSb layer deposited in a hydrogen plasma at a substrate temperature of 410 °C on a GaAs (100) substrate are about 6×1016cm−3and 750 cm2/Vs, respectively, which are comparable to those obtained by other methods like molecular beam epitaxy, metalorganic chemical vapor deposition etc., in spite of a lower substrate temperature in PAE.

ISSN:0003-6951    

DOI:10.1063/1.94837

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The epitaxial regrowth of silicon implanted with both argon and boron is performed by isochronal furnace and cw laser annealing. Argon is found to enhance the thermal anneal threshold for boron‐silicon reordering, while itself exhibiting essentially no redistribution after annealing. Boron, by comparison, increases the solid‐phase regrowth velocity and prevents the outdiffusion of argon. Based on these findings, a methodology for forming and preserving shallow boron junctions is suggested.

ISSN:0003-6951    

DOI:10.1063/1.94838

出版商:AIP    

年代:1984

数据来源: AIP