1. |
Effect of photodeposited iron oxide and tin oxide on the consolidation of porous Vycor glass |
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Applied Physics Letters,
Volume 57,
Issue 3,
1990,
Page 209-211
E. A. Mendoza,
D. Sunil,
E. Wolkow,
H. D. Gafney,
M. H. Rafailovich,
J. Sokolov,
G. G. Long,
P. R. Jemian,
S. A. Schwartz,
B. J. Wilkens,
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摘要:
Iron oxide and tin oxide have been photodeposited in porous Vycor glass and examined before and after consolidation of the glass. Scanning electron microscopy reveals that the iron oxide particles are larger than the tin oxide particles. However, small‐angle x‐ray scattering and Rutherford backscattering show that the glass consolidates about the iron oxide but not about the tin oxide. Photodeposition of tin oxide, which appears to chemically modify the glass surface and to prevent its consolidation, offers a means of producing highly resolved regions of porosity in the otherwise consolidated glass.
ISSN:0003-6951
DOI:10.1063/1.103740
出版商:AIP
年代:1990
数据来源: AIP
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2. |
Measurement of the two‐photon absorption coefficient in a GaAs/AlGaAs quantum well laser |
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Applied Physics Letters,
Volume 57,
Issue 3,
1990,
Page 212-214
H. Q. Le,
H. K. Choi,
C. A. Wang,
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摘要:
The two‐photon absorption (TPA) coefficient has been measured for a single‐mode GaAs/AlGaAs quantum well laser at 0.86 &mgr;m, near the lasing wavelength of 0.83 &mgr;m. Picosecond laser pulses were employed to resolve the ultrafast TPA from long‐lived carrier‐dependent effects. The TPA coefficient was found to be 31±6 cm GW−1, which corresponds to a value of (5.7±1.2)×10−11esu for the imaginary part of the third‐order nonlinear susceptibility. At wavelengths near the quantum well exciton, no strong resonance enhancement of the two‐photon transition was observed, and the coefficient appears to be characteristic of the AlGaAs cladding layers.
ISSN:0003-6951
DOI:10.1063/1.103741
出版商:AIP
年代:1990
数据来源: AIP
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3. |
Detailed analysis of second‐harmonic generation near 10.6 &mgr;m in GaAs/AlGaAs asymmetric quantum wells |
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Applied Physics Letters,
Volume 57,
Issue 3,
1990,
Page 215-217
P. Boucaud,
F. H. Julien,
D. D. Yang,
J‐M. Lourtioz,
E. Rosencher,
P. Bois,
J. Nagle,
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摘要:
We report on the observation of resonant intersubband second‐harmonic generation in asymmetric GaAs/AlGaAs quantum wells using a cw orQ‐switched tunable CO2laser as the pumping source. The dependence of the second‐harmonic intensity with the pump photon wavelength is presented for the first time. A Lorentzian‐like second‐harmonic line shape is found with a maximum at 10.9 &mgr;m and a linewidth of 0.4 &mgr;m (4.1 meV). These results are in good agreement with theoretical predictions. The expected quadratic dependence of the second‐harmonic conversion efficiency with pump intensity is well verified for intensities up to 150 kW/cm2. The calibrated second‐harmonic power reaches 0.13 &mgr;W for a cw pump power of 0.8 W. The value of 7.2×10−7m/V deduced for the second‐order nonlinear susceptibility is about 1900 times greater than that found in bulk GaAs.
ISSN:0003-6951
DOI:10.1063/1.103742
出版商:AIP
年代:1990
数据来源: AIP
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4. |
Transverse mode characteristics of vertical cavity surface‐emitting lasers |
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Applied Physics Letters,
Volume 57,
Issue 3,
1990,
Page 218-220
C. J. Chang‐Hasnain,
M. Orenstein,
A. Von Lehmen,
L. T. Florez,
J. P. Harbison,
N. G. Stoffel,
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摘要:
Transverse mode characteristics of vertical cavity surface‐emitting (VC‐SE) lasers are described. The mode structure is investigated as a function of the transverse dimension for proton‐implanted gain‐guided VC‐SE lasers. A comparison is made to an air‐post index‐guided structure. The lasing modes and the evolution of the modes with increasing drive current for the VC‐SE lasers are observed to be highly analogous to those of the edge‐emitting lasers. Broad‐area gain‐guided lasers lase in the fundamental TEM00mode near threshold. At higher currents, high‐order modes are successively excited. A 5 &mgr;m square proton‐implanted gain‐guided VC‐SE laser emits a single mode. On the other hand, an air‐post index‐guided SE laser, due to the large index difference between the laser and the cladding, emits multiple transverse modes. Moreover, we show that the gain‐guided VC‐SE lasers exhibit better device characteristics than the air‐post index‐guided lasers.
ISSN:0003-6951
DOI:10.1063/1.103743
出版商:AIP
年代:1990
数据来源: AIP
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5. |
Second‐harmonic generation of a new chalcone‐type crystal |
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Applied Physics Letters,
Volume 57,
Issue 3,
1990,
Page 221-223
G. J. Zhang,
T. Kinoshita,
K. Sasaki,
Y. Goto,
M. Nakayama,
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摘要:
A new type of chalcone crystal was prepared. Anisotropic indices with wavelength dispersion were measured by the Brewster angle method. The two largest second‐harmonic generation (SHG) tensor components were determined by the wedge method and compared withd11of 2‐methyl‐4‐nitroaniline. Calculated collinear and noncollinear phase‐matched SHG patterns reasonably fit the observed photographs.
ISSN:0003-6951
DOI:10.1063/1.103744
出版商:AIP
年代:1990
数据来源: AIP
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6. |
High power output 1.48–1.51 &mgr;m continuously graded index separate confinement strained quantum well lasers |
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Applied Physics Letters,
Volume 57,
Issue 3,
1990,
Page 224-226
T. Tanbun‐Ek,
R. A. Logan,
N. A. Olsson,
H. Temkin,
A. M. Sergent,
K. W. Wecht,
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摘要:
A record high power output strained‐layer InGaAs/InP quantum well laser emitting at 1.48 to 1.51 &mgr;m is demonstrated. Maximum cw output as high as 206 mW is obtained from a sample with a cavity length of 890 &mgr;m and a facet reflectivity of ∼5 and 85% for the front and the rear facets, respectively. The laser has a threshold of 30 mA and a slope efficiency as high as 0.4 mW/mA.
ISSN:0003-6951
DOI:10.1063/1.103722
出版商:AIP
年代:1990
数据来源: AIP
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7. |
GaAs traveling‐wave directional coupler optical modulator/switch |
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Applied Physics Letters,
Volume 57,
Issue 3,
1990,
Page 227-228
Hideki Hayashi,
Kunio Tada,
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摘要:
Device structure, fabrication method, and experimental results of a GaAs/AlGaAs traveling‐wave directional coupler optical modulator/switch operated at 1.06 &mgr;m wavelength are described for the first time. An extinction ratio of 13.7 dB has been measured at the switching voltage of 10.4 V, and a 3 dB bandwidth of 9.1 GHz has been demonstrated for a device with a waveguide width of 5.5 &mgr;m, waveguide spacing of 3.5 &mgr;m, and length of 8 mm.
ISSN:0003-6951
DOI:10.1063/1.103723
出版商:AIP
年代:1990
数据来源: AIP
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8. |
All solid‐state cw passively mode‐locked Ti:sapphire laser using a colored glass filter |
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Applied Physics Letters,
Volume 57,
Issue 3,
1990,
Page 229-230
Nobuhiko Sarukura,
Yuzo Ishida,
Tsutomu Yanagawa,
Hidetoshi Nakano,
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摘要:
All solid‐state cw passive mode locking of a Ti:sapphire laser is accomplished using a colored glass filter, instead of an organic dye, as a saturable absorber. The tuning range is remarkably wide (785–855 nm), and 2.7 ps pulses are obtained directly from the cavity.
ISSN:0003-6951
DOI:10.1063/1.103724
出版商:AIP
年代:1990
数据来源: AIP
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9. |
Identification ofH2(&ngr;″)vibrational excitation processes in a hydrogen discharge |
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Applied Physics Letters,
Volume 57,
Issue 3,
1990,
Page 231-233
J. R. Hiskes,
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摘要:
The enhancement of theH2(&ngr;″)vibrational distribution observed in the medium‐density hydrogen discharge of Eenshuistra and co‐workers is investigated theoretically as a function of different excitation processes. The observed fivefold enhancement of the&ngr;″=5population with increasing discharge current is reproduced in the model. Principal excitations generating this enhancement areH+3surface recombination and fast‐electron excitation. Atom‐surface recombination may be a principal contributor near the&ngr;″=1portion of the spectrum.
ISSN:0003-6951
DOI:10.1063/1.103725
出版商:AIP
年代:1990
数据来源: AIP
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10. |
Dynamic behavior of two‐laser‐induced bubbles in water |
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Applied Physics Letters,
Volume 57,
Issue 3,
1990,
Page 234-236
Y. Tomita,
A. Shima,
K. Sato,
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摘要:
Two bubbles are simultaneously generated in water by focusing aQ‐switched ruby laser. The dynamic behavior of the induced bubbles is investigated by means of high‐speed photography. Consequently it is found that the bubble–bubble interaction is significantly influenced not only by the relative size of bubbles but also by the mutual distance between them. When two bubbles are axisymmetrically produced one behind the other near a rigid wall, we can observe a very interesting phenomenon, bubble splitting followed by bubble pinching.
ISSN:0003-6951
DOI:10.1063/1.103726
出版商:AIP
年代:1990
数据来源: AIP
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