摘要:

Broad‐band vacuum ultraviolet (VUV) fluorescence has been observed in Nd3+‐, Er3+‐, and Tm3+‐doped LaF3, YF3, LiYF4, and LuF3by electron‐beam and VUV excitation. The VUV excitation spectra indicate a large Stokes shift (≳5000 cm−1) and a high fluorescence quantum yield of 0.8. The threshold power for laser action in these crystals by optical pumping has been estimated. Using a molecular H2laser as a pumping source, a laser system which is tunable from 1650 to 2600 A˚ could be constructed.

ISSN:0003-6951    

DOI:10.1063/1.89137

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Half‐ring waveguides (5 &mgr;m width, 185 &mgr;m radius) fabricated by liquid‐phase expitaxial growth of Ga1−xAlxAs and GaAs layers over preferentially etched channels in GaAs substrates were made to lase by optical pumping with a N2laser (&lgr;=3371 A˚) at 77 °K. The half‐ring lasers had a threshold of about 2×104W/cm2; a bending loss per radian &agr;c<1.5 cm−1; strong TE polarization; and a well‐defined circumferential mode structure: &Dgr;&lgr;≃1.07 A˚ at &lgr;=8280 A˚ for a 580‐&mgr;m‐long cavity. Straight guides of similar profile to the circular guides were made to lase for comparison. A calculated 0.5‐A˚ mode broadening due to transient heating during the pump laser pulse accounts for the observed lasing spectra.

ISSN:0003-6951    

DOI:10.1063/1.89138

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

This letter describes a small N2laser using discrete capacitors in a Blumlein‐type circuit with a 15‐cm‐long discharge length which yields 170‐kW peak power in a 5.5‐nsec pulse at 17‐kV charging voltage. The high‐power conversion efficiency of 0.065% attained is attributed to the low inductance of the circuit and the use of an external optical cavity.

ISSN:0003-6951    

DOI:10.1063/1.89139

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

A frequency multiplexing light source is realized by monolithically integrating GaAs‐GaAlAs distributed‐feedback diode lasers with different grating periods and passive waveguides on a GaAs substrate. The lasers with wavelength separation of ∼20 A˚ are modulated independently, and the output beams are obtained from a common launching waveguide.

ISSN:0003-6951    

DOI:10.1063/1.89140

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Photoinduced restoration of once‐weakened fluorescence has been found in rhodamine‐6G–doped polyurethane film. Formation and annihilation of the quencher of the fluorescence by the irradiation of laser light seems to be closely related to the disappearance and restoration of the fluorescence.

ISSN:0003-6951    

DOI:10.1063/1.89148

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Sustained growth of long lengths of silicon ribbons by the edge‐defined film‐fed growth (EFG) technique is shown to result in the attainment of an ’’equilibrium’’ defect structure and orientation by the crystals. The structure consists of parallel defect boundaries parallel to the edges of the ribbon with a ribbon orientation of {110} ⟨211⟩. The influence of seed orientation on the attainment of this structure has been examined.

ISSN:0003-6951    

DOI:10.1063/1.89123

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

It was found that sintered alloys having a composition of approximatelyz=8 in Sm(Co0.85Fe0.05Cu0.10)zexhibit a high coercive force on the order of 10 kOe, for 5–10‐&mgr;m average grain size. Magnetization and demagnetization curves showed that the coercive force is controlled by a nucleation process. Attempts were made to achieve a high density without serious grain growth by means of high‐pressure isostatic compaction and hot pressing, resulting in 96% of the density and 7‐&mgr;m average grain size. With this approach,Br=10.3kG,IHc=10.2 kOe, and a maximum energy product of 22.0 MG Oe were achieved.

ISSN:0003-6951    

DOI:10.1063/1.89149

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

SE yield (&dgr;0) data can be interpreted in terms of the Fano plot, thereby yielding a simple formulation of &dgr;0with respect to the incident electron energyTand a correlation between the mean ionization potential ⟨I⟩ and a parameter in the Fano plot.

ISSN:0003-6951    

DOI:10.1063/1.89150

出版商:AIP    

年代:1976

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.89197

出版商:AIP    

年代:1976

数据来源: AIP