摘要:

We report the suppression of low‐frequency noise in the He&sngbnd;Ne and argon lasers as a result of mode coupling by means of an internal phase modulator. Suppression of off‐axis modes and 20 to 30 dB of low‐frequency AM noise suppression have been obtained in both FM and phase‐locked operation, with no loss of output power.

ISSN:0003-6951    

DOI:10.1063/1.1651836

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Experimental evidence is presented which (1) allows quantitative determination of the redistribution of Si impurities between Ga and As sites after Li diffusion; (2) shows there is no loss of Si to complex or pair formation whenNSi∼ 1−2 × 1018cm−3; and (3) indicates that the site symmetry of the Si is tetrahedral before and after redistribution.

ISSN:0003-6951    

DOI:10.1063/1.1651837

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

The second harmonic pulse shape generated from ultrashort pulses is calculated. In long dispersive crystals the pulse width may be much broader than the incident pulse and the power conversion ratio may saturate at a low value. These effects should be prominent in LiNbO3with 4 × 10−13sec pulses.

ISSN:0003-6951    

DOI:10.1063/1.1651838

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

Holograms of naturally illuminated objects are synthesized in two steps. A stereoscopic camera technique is used to record the objects' parallax qualities in white light; this photographic information is transformed into a hologram with coherent light. The image quality is excellent, and the method seems practical for making full‐color reconstructions using stereoscopic photographs taken with color film.

ISSN:0003-6951    

DOI:10.1063/1.1651831

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

The generation of surface elastic waves by the transient surface heating of piezoelectric and nonpiezoelectric solids is described. AQ‐switched ruby laser produces the surface heating; the frequencies of the resultant surface waves are Fourier components of the laser waveform. The use of a spatially periodic illumination is shown to increase the effectiveness of generation at a selected frequency. This method of generating surface waves appears suitable for microwave frequency operation as well as operation at high wave amplitudes at low frequencies.

ISSN:0003-6951    

DOI:10.1063/1.1651832

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

The microwave transmission characteristics of the ferromagnetic semiconductor CdCr2Se4doped with Ag have been measured as function of the applied magnetic and electric field. The results are interpreted in terms of active helicon‐spin wave interactions; and the agreement between experiment and theory is found to be very good qualitatively.It is believed that the results presented in this Letter represent the first published evidence for active helicon‐spin wave interactions.

ISSN:0003-6951    

DOI:10.1063/1.1651833

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

We have observed that at certain levels of laser power, an argon ion laser oscillates in only two strong modes. The frequency difference between these two modes is an integer multiple of the cavity fundamental beat frequency and increases with the laser power. Analysis of this effect shows that pulses from such a laser are 0.3&pgr; rather than &pgr; pulses.

ISSN:0003-6951    

DOI:10.1063/1.1651834

出版商:AIP    

年代:1968

数据来源: AIP

摘要:

The shift of the frequency of oscillation of the 00°1–10°0 rotation‐vibration band at 10.6 &mgr; of a CO2laser has been investigated as a function of total pressure, CO2partial pressure, discharge current, and cavity mode position. The measurements were made by heterodyning two passively stabilized CO2lasers, both oscillating in a single transverse mode and single frequency at thePbranch of the 00°1–10°0 rotation‐vibration band of CO2. The result yielded a 5–8 MHz/torr frequency shift toward red due to an increase in total pressure and a 500–900 kHz/mA shift toward blue due to an increase in excitation. The amount of frequency shift due to excitation was found to be independent of the location of the cavity resonance with respect to the Doppler center. The dependence on CO2partial pressure was also determined.

ISSN:0003-6951    

DOI:10.1063/1.1651835

出版商:AIP    

年代:1968

数据来源: AIP