1. |
Amplified spontaneous emission in Tm3+‐doped monomode optical fibers in the visible region |
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Applied Physics Letters,
Volume 57,
Issue 21,
1990,
Page 2169-2171
A. S. L. Gomes,
Cid B. de Araujo,
B. J. Ainslie,
S. P. Craig‐Ryan,
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摘要:
We report the observation of amplified spontaneous emission in silica‐based single‐mode optical fibers doped with Tm3+. Frequency upconverted emission was observed in a number of visible and near‐infrared lines after pumping by 1064 nm radiation. The upconversion process is induced via the nonlinear absorption of the infrared beam and enhanced by stimulated Raman scattering in the fiber, leading to amplified spontaneous emission in the blue (∼473 nm) region.
ISSN:0003-6951
DOI:10.1063/1.103924
出版商:AIP
年代:1990
数据来源: AIP
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2. |
High average power edge emitting laser diode arrays on silicon microchannel coolers |
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Applied Physics Letters,
Volume 57,
Issue 21,
1990,
Page 2172-2174
D. Mundinger,
R. Beach,
W. Benett,
R. Solarz,
V. Sperry,
D. Ciarlo,
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摘要:
We have demonstrated high average power output devices in both one‐dimensional (1‐D) and two‐dimensional (2‐D) arrays of laser diodes using efficient edge emitting cleaved bars and silicon microchannel coolers. These packages are based on the rack and stack architecture. For the 1‐D array a cw optical power output of 22.2 W was obtained with 20% electrical to optical conversion efficiency. For the 2‐D array an average optical power density of greater than 100 W/cm2was obtained at an efficiency of 25%.
ISSN:0003-6951
DOI:10.1063/1.103925
出版商:AIP
年代:1990
数据来源: AIP
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3. |
Fission‐fragment‐excited lasing at 585.3 nm in He/Ne/Ar gas mixtures |
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Applied Physics Letters,
Volume 57,
Issue 21,
1990,
Page 2175-2177
G. A. Hebner,
G. N. Hays,
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摘要:
Fission‐fragment‐excited lasing is reported for the 3p’(1/2)0–3s’(1/2)01neon transition (&lgr;=585.3 nm) in mixtures of He/Ne/Ar. The laser power efficiency peaks at a He/Ne/Ar ratio of approximately 50/2/1 for a laser cell pressure of 1.9 atmospheres. Laser parameters for pump rates from 70 to 1200 W/cm3are presented for three cavity configurations.
ISSN:0003-6951
DOI:10.1063/1.103926
出版商:AIP
年代:1990
数据来源: AIP
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4. |
Emission spectroscopy during excimer laser ablation of graphite |
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Applied Physics Letters,
Volume 57,
Issue 21,
1990,
Page 2178-2180
Xiangli Chen,
Jyoti Mazumder,
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摘要:
Emission spectrum of the laser‐induced plasma plume is obtained during KrF excimer laser ablation of graphite in argon and hydrogen gas mixture for deposition of diamond‐like films. Bands of C2and CN molecules dominate the spectrum while weak CI, CII, and H&agr;lines are also observed. From the emission intensities, molecular vibrational temperature is calculated to be (12–15)×103K, and concentrations are estimated to be N(C2)=5×1014cm−3and N(CN)=2×1014cm−3.
ISSN:0003-6951
DOI:10.1063/1.103927
出版商:AIP
年代:1990
数据来源: AIP
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5. |
Frequency stabilization of an external‐cavity diode laser |
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Applied Physics Letters,
Volume 57,
Issue 21,
1990,
Page 2181-2183
W. David Lee,
Joe C. Campbell,
R. J. Brecha,
H. J. Kimble,
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摘要:
Using a hybrid optical/electronic technique, an external‐cavity diode laser was frequency stabilized with respect to the sub‐Doppler spectrum of cesium vapor. Laser linewidths of 65 kHz and frequency stabilities of ±10 kHz were obtained.
ISSN:0003-6951
DOI:10.1063/1.103928
出版商:AIP
年代:1990
数据来源: AIP
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6. |
Effects of strain in multiple quantum well distributed feedback lasers |
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Applied Physics Letters,
Volume 57,
Issue 21,
1990,
Page 2184-2186
T. Tanbun‐Ek,
R. A. Logan,
S. N. G. Chu,
A. M. Sergent,
K. W. Wecht,
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摘要:
A survey of graded‐index separate confinement multiple quantum well distributed feedback lasers comparing the effects of strain in the quantum well upon threshold, output power, and linewidth is reported. Lasers with either compressive or tensile strained quantum wells and a long cavity length (890 &mgr;m) show lower threshold current (10–20 mA) as well as lower linewdith power product than lasers with unstrained quantum wells and have a comparable minimum linewidth to the unstrained quantum well lasers. A minimum linewidth as narrow as 900 and 440 kHz for compressive strain and unstrained quantum well lasers, respectively, was obtained at output power of 30 mW. Single longitudinal mode operation with a maximum output power over 80 mW was observed in all the structures.
ISSN:0003-6951
DOI:10.1063/1.103929
出版商:AIP
年代:1990
数据来源: AIP
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7. |
Ion beam induced conductivity in chemically vapor deposited diamond films |
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Applied Physics Letters,
Volume 57,
Issue 21,
1990,
Page 2187-2189
S. Prawer,
A. Hoffman,
R. Kalish,
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摘要:
Polycrystalline diamond films deposited by the microwave plasma chemical vapor deposition (CVD) technique onto quartz substrates have been irradiated with 100 keV C and 320 keV Xe ions at room temperature and at 200 °C. The dose dependence of the electrical conductivity measuredinsituexhibited complicated, nonmonotonic behavior. High doses were found to induce an increase of up to ten orders of magnitude in the electrical conductivity of the film. The dose dependence of the conductivity for the CVD films was found to be very similar to that measured for natural, type IIa, single‐crystal diamonds irradiated under identical conditions. This result suggests that the conduction mechanism in ion beam irradiated polycrystalline CVD diamond films is not dominated by grain boundaries and graphitic impurities as one might have expected, but rather is determined by the intrinsic properties of diamond itself.
ISSN:0003-6951
DOI:10.1063/1.103931
出版商:AIP
年代:1990
数据来源: AIP
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8. |
Enhancement of group III atom interdiffusion by nondopant oxygen implants in In0.53Ga0.47As‐In0.52Al0.48As multiquantum wells |
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Applied Physics Letters,
Volume 57,
Issue 21,
1990,
Page 2190-2192
E. V. K. Rao,
P. Ossart,
H. Thibierge,
M. Quillec,
P. Krauz,
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摘要:
We show here that the implants of oxygen, a basically nondopant impurity, after adequate high‐temperature annealings (for example, 750 °C, 1 h furnace anneal) lead to a significant interdiffusion of group III atoms in molecular beam epitaxy grown In0.53Ga0.47As‐In0.52Al0.48As multiquantum wells (MQWs). Both photoluminescence and Auger electron spectroscopy measurements (coupled to Ar+ion etching) have been employed to monitor disordering in MQWs implanted with oxygen (5×1013to 5×1014ions cm−2) and subsequently annealed using either rapid thermal anneals or long duration furnace anneals. The role of oxygen to enhance group III atom (Al, Ga, and In) interdiffusion is unambiguously established and a tentative explanation based on a possible migration of oxygen in these MQWs is proposed and dissussed.
ISSN:0003-6951
DOI:10.1063/1.103932
出版商:AIP
年代:1990
数据来源: AIP
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9. |
Growth of oxide layers on gallium arsenide with a high kinetic energy atomic oxygen beam |
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Applied Physics Letters,
Volume 57,
Issue 21,
1990,
Page 2193-2195
M. A. Hoffbauer,
J. B. Cross,
V. M. Bermudez,
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摘要:
Oxide layers have been formed on (110) and (100) GaAs wafers by exposure to a high kinetic energy beam of atomic O and characterized using x‐ray photoemission spectroscopy (with Ar+ion sputter profiling) and Raman spectroscopy. Photoemission shows the reacted layer, ∼500 A˚ thick, to be uniform in composition and fully oxidized. Raman spectroscopy shows that the substrate is not appreciably disordered during oxidation and in some cases no free‐elemental As is present at the oxide‐substrate interface at a detectable level.
ISSN:0003-6951
DOI:10.1063/1.103933
出版商:AIP
年代:1990
数据来源: AIP
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10. |
Anomalies of hypersonic velocity and attenuation in vinylidene fluoride‐trifluoroethylene copolymer from Brillouin scattering |
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Applied Physics Letters,
Volume 57,
Issue 21,
1990,
Page 2196-2198
Zhimin Liu,
V. Hugo Schmidt,
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摘要:
The hypersonic behavior of a vinylidene fluoride and trifluoroethylene (70/30 mol %) copolymer has been investigated by Brillouin scattering without using index matching liquid. Both the glass and ferroelectric transitions are clearly seen in the acoustic behavior. The home‐prepared sample has excellent optical properties and let us obtain sound attenuation information in the temperature range of 23–123 °C, which another investigator did not discuss because of the bad optical properties of the sample surface. Anomalies of sound attenuation near the transition point have been observed.
ISSN:0003-6951
DOI:10.1063/1.103934
出版商:AIP
年代:1990
数据来源: AIP
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