摘要:

We report a novel optoacoustic detection scheme which is suited for use with low‐power radiation sources. The improved detection capability is demonstrated for SO2with a frequency‐doubled dye laser of 1 mW uv output power, allowing the detection of SO2concentrations as low as 0.12 ppb.

ISSN:0003-6951    

DOI:10.1063/1.90023

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A closed‐cycle recirculating system is described which enables prolonged operation of a rare‐gas halide excimer laser on a single charge of rare‐gas mixture. The flowing gas is continuously purified in a high‐temperature titanium gettering furnace, following removal of the halogen by reaction to form a volatile, but condensable, metal halide. The halogen is reintroduced after the rare‐gas purification, being consumed in the operation of the laser along with the gettering metal.

ISSN:0003-6951    

DOI:10.1063/1.90024

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The paper reports the formation of optical waveguides in LiNbO3by the implantation of helium ions. The ion beam damage defines the low‐index regions which surround the waveguide. The computed index profile and the observed modes are in agreement. Changes inn0of up to 7% are recorded as a saturation index change.

ISSN:0003-6951    

DOI:10.1063/1.90025

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The achievement of room‐temperature (300 °K) operation of Ga(1−x)AlxAs‐GaAs double‐heterostructure lasers with active layers of quantum‐well dimensions ∼200 A˚ thick is reported. These devices are grown by metalorganic chemical vapor deposition and exhibit pronounced effects in the spectral and lasing characteristics that are related to the small active region thickness and are the first such effects observed for DH lasers in the GaAlAs‐GaAs system.

ISSN:0003-6951    

DOI:10.1063/1.90026

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The influence of F2vibrational excitation and direct dissociation by electron impact is examined for conditions typical of electron‐beam‐sustained KrF* lasers. For values of F2fractional concentration greater than about 0.003 the results of this analysis indicate that the dissociation processe+F2→2F+emay significantly affect electron‐metastable atom production efficiency, rare gas–halide excimer production efficiency, and gain.

ISSN:0003-6951    

DOI:10.1063/1.90027

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

This letter reports an optical waveguide TE‐TM mode splitter using coupling between nonidentical waveguides. The experimental mode splitter was fabricated from glass compositions, and TE0‐TM0mode splitting has been demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.90028

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Time‐resolved ion spectra of the collisionless ionization of D2O was measured. The ionization was energy density dependent with different thresholds for different species of ions.

ISSN:0003-6951    

DOI:10.1063/1.90029

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Double‐heterojunction Al0.3Ga0.7As/Al0.08Ga0.92As lasers (oxide‐striped and Al2O3facet coated) were subjected to step‐temperature aging from 60 to 100 °C. The change in threshold current and spontaneous output was monitored at 22 °C. The average time required for a 20% pulsed threshold current increases from about 500 h, when operating at 100 °C, to about 5000 h at 70 °C. At 22 °C, the extrapolated time is about 106h. The time needed for a 50% spontaneous emission reduction is of the same order of magnitude. The resulting ’’activation energies’’ are ∼0.95 eV for laser degradation and ∼1.1 eV for the spontaneous output decrease.

ISSN:0003-6951    

DOI:10.1063/1.90030

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Lyman‐&agr; radiation due to near‐resonant preferred charge transfer in the systems Cs‐H+and Na‐H+was observed for proton fluxes of up to 3×1021cm−2 sec−1and alkali densities of up to 1014cm−3. These results with a plasma gun provide a significant first step towards vuv lasing with such systems.

ISSN:0003-6951    

DOI:10.1063/1.90031

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A new laser structure, the strip buried heterostructure (SBH) laser, using an active layer strip 2.5 to 10 &mgr;m in width, on a low‐loss waveguide is described. Typical test results with pulsed injection, for a 5‐&mgr;m strip width, show stable fundamental‐transverse‐mode operation linear light‐current characteristics up to 15 times threshold where the power output is 230 mW/mirror (without AR coating). Single‐longitudinal‐mode oscillation has also been observed up to twice threshold. Far‐field beam divergence of 8°–10° and 26°–30° was obtained in directions parallel and perpendicular to the junction plane, respectively.

ISSN:0003-6951    

DOI:10.1063/1.90032

出版商:AIP    

年代:1978

数据来源: AIP