摘要:

A traveling wave maser using iron doped rutile (Fe3+: TiO2) has been developed for a signal frequency of 86–88 GHz. The 3‐dB bandwidth is 40–50 MHz for an electronic gain of 36 dB and a net maser gain of 15–20 dB. Hexagonal aluminum substituted strontium ferrite was used for isolation. A unique overmoded ridge guide structure is used to match pump and signal power to the active material from 30 to 120 GHz. The maser noise temperature has been measured asTMaser=20±10 K.

ISSN:0003-6951    

DOI:10.1063/1.90996

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

Tunable single‐longitudinal‐mode operation of a transversely excited atmospheric (TEA) CO2laser has been achieved using an injection technique with a cw waveguide laser as the master oscillator. Tunability in excess of 300 MHz from the CO2line center is reported for various CO2lines. A high resolution spectrum of an ozone absorption feature has been recorded using this technique.

ISSN:0003-6951    

DOI:10.1063/1.90997

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

Operation of cw Ni : MgF2and Co : MgF2lasers with an external cavity has produced broadly tunable emission in the near infrared. The Ni : MgF2laser was tuned continuously from 1.61 to 1.74 &mgr;m and the Co : MgF2laser from 1.63 to 2.08 &mgr;m. Optical pumping with a 1.32‐&mgr;m Nd : YAG laser and conduction cooling of the laser crystals to 80 K yielded stable spiking‐free TEM00outputs from both lasers with maximum cw output powers of about 100 mW. The Ni : MgF2laser was operated with a single‐frequency output of 20 mW and wasQswitched to generate a peak power output of 140 W at a 100‐Hz repetition rate.

ISSN:0003-6951    

DOI:10.1063/1.90998

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

The state of polarization at the output end of a long nominally circular single‐mode optical fiber is stabilized by an active control system. It contains a polarimeter and two electromagnetic fiber squeezers which introduce variable amounts of stress birefringence directly into the fiber, compensating for the effects of changing intrinsic fiber birefringence.

ISSN:0003-6951    

DOI:10.1063/1.90999

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

We report high‐resolution absorption spectroscopy of powdered microsamples using a pulsed laser and a gated optoacoustic detection technique. Our method is simple, sensitive, and easily adaptable for cryogenic cooling of the sample. Quantitative data for Ho2O3, Dy2O3, and Er2O3powdered crystals are obtained, and identification and analysis of the observed spectral lines are given for Dy2O3and Er2O3.

ISSN:0003-6951    

DOI:10.1063/1.91000

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

Under suitable conditions, the boundary between a linear and a nonlinear (Kerr effect) medium should have a reflection coefficient which exhibits hysteresis as a function of optical intensity. We present the first experimental evidence of this effect. Experiments were performed using ∼1‐ns ruby laser pulses incident on a glass‐CS2boundary.

ISSN:0003-6951    

DOI:10.1063/1.91001

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

We have constructed a magnetically insulated ion source in which deuterons are extracted from plasma generated by a deuterated titanium washer located within the field excluding anode. Peak beam parameters are 0.8 A/cm2at 140 kV for 0.4 &mgr;sec with a 14‐mm anode‐cathode gap. Faraday cup measurements show significantly fewer impurities in the deuteron beam than in proton beams extracted from surface flashover plasma.

ISSN:0003-6951    

DOI:10.1063/1.91002

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

The effective Debye screening length is shown to be increased in the presence of a high‐power electromagnetic wave. The consequent modifications in ponderomotive redistributive effects and strong violations of charge neutrality have been shown to be in agreement with recent laser‐plasma experiments.

ISSN:0003-6951    

DOI:10.1063/1.90980

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

The possibility of shell disintegration in thin‐wall targets as indicated by mixing of target surface material into the compressing core in laser‐induced implosions has been investigated. Aluminum coated glass microballoon targets were irradiated by a two‐beam Nd:phosphate glass laser with laser power up to 250 GW on target. The occurrence of mixing in these exploding pusher implosions was determined by using spatially resolved x‐ray spectroscopy. Mixing was not observed except for laser shots with an intentional prepulse (∼10 mJ, 1.5 nsec before the main pulse).

ISSN:0003-6951    

DOI:10.1063/1.90981

出版商:AIP    

年代:1979

数据来源: AIP

摘要:

A new method of estimating effective macroscopic elastic constants for microscopically inhomogeneous materials is formulated using elastic‐wave scattering theory. The self‐consistent medium is determined by the condition that the scattered long‐wavelength displacement field must vanish on the average. The resulting formulas are simpler to apply than previous methods due to the reduction from tensor to vector equations. Our formulas are automatically symmetric under interchange of constituent labels whereas some other ’’self‐consistent’’ formulations for needle and disk inclusions do not possess this property. For spherical inclusions, the standard self‐consistent elastic constants are reproduced.

ISSN:0003-6951    

DOI:10.1063/1.90982

出版商:AIP    

年代:1979

数据来源: AIP