摘要:

Employing polymethine dyes as saturable absorbers and intracavity Fabry‐Perot interferometers, a flashlamp‐pumped cresyl‐violet dye laser has been mode locked to produce picosecond pulses (3–5 psec) frequency tunable from 644 to 704 nm. The frequency tuning ranges of mode‐locked rhodamine 6G and rhodamine B dye lasers have also been extended to cover 584 to 645 nm.

ISSN:0003-6951    

DOI:10.1063/1.1654074

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Acoustic‐surface‐wave convolution by nonlinear mixing has been observed in cubic, hexagonal, and trigonal crystals. The magnitudes of the phenomenological nonlinear surface‐wave coupling constants are tabulated and compared with the linear electromechanical coupling factor 2(&Dgr;V/V). It has been found that the basal plane of PZT‐8 has a larger nonlinear coupling constant than that of the commonly usedY‐cutZ‐propagating LiNbO3.

ISSN:0003-6951    

DOI:10.1063/1.1654075

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The effect of kinetic cooling due to the absorption of 10.6‐&mgr; CO2laser radiation in the atmosphere has recently been predicted. In this letter, experimental evidence for this effect is presented. Transient‐density increases due to the kinetic cooling have been observed in CO2&sngbnd;N2mixtures following the propagation of an ∼ 1‐&mgr;sec 0.5‐J CO2laser pulse through the gas. The experiments were performed with varying concentrations of CO2and the observed cooling and subsequent heating effects are explained using the usual three‐level approximation for vibrational‐energy transfer in CO2&sngbnd;N2, together with known relaxation rates.

ISSN:0003-6951    

DOI:10.1063/1.1654076

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The highest absolute frequency measurement yet reported is described. The frequency of the 3.39‐&mgr; line from a He&sngbnd;Ne laser oscillating at the methane absorption frequency was found to be 88.376245 (55) THz. The frequency was measured by beating the 88‐THz radiation with theR(30) line from a cw CO2laser and a 48‐GHz klystron in a tungsten‐on‐nickel point‐contact diode. The speed of light calculated from this frequency and previous wave‐length measurements is in agreement with the accepted value and of comparable accuracy.

ISSN:0003-6951    

DOI:10.1063/1.1654077

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Optical transmission, refractive‐index, and nonlinear optical properties of single domain PbTiO3have been measured between room temperature and the Curie temperatureTc. The second‐harmonic coefficientd31is found to be the highest for any room‐temperature ferroelectric. Since the birefringence is small (approximately 0.008), phase‐matched SHG is not possible, but nondegenerate three‐frequency mixing should be possible. The Miller &dgr; coefficients are analyzed in terms of Jerphagnon's formulation and poor agreement is observed.

ISSN:0003-6951    

DOI:10.1063/1.1654078

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Laser action on the CO vibrational‐rotational bands between 4.8 and 5.3 &mgr; is produced by electrical excitation of CO : N2: O2: He mixtures followed by expansion in a supersonic nozzle. Conversion of electrical energy into laser output occurs with ∼ 2% efficiency and small‐signal gains in excess of 0.8% cm−1have been observed.

ISSN:0003-6951    

DOI:10.1063/1.1654079

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

A tunable (0.567–0.605 &mgr;) solid‐state dye laser with a small active volume (10 &mgr;×80 &mgr;×1 cm), which uses a nondestructively read‐reversible optical‐memory material to control the intensity and wavelength of the laser emission, is described. The optical‐memory material, photodimers of acridizinium ethylhexanesulfonate, provides distributed feedback in the form of an adjustable‐period phase grating which can be optically written (0.364 &mgr;) or erased (0.313 &mgr;). Reproducibility of laser switching, time and spectral structure, and operation at low temperatures where photodegradation of the dye is significantly reduced are discussed.

ISSN:0003-6951    

DOI:10.1063/1.1654080

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

A flash‐pumped Nd:YAG laser has been effectivelyQswitched with an acousto‐optic beam deflector in a resonator arranged such that the deflected laser beam goes into feedback while the undeflected beam is the output. This allows the laser threshold, and consequently the output pulse energy, to be electronically controlled via the rf power applied to the deflector permitting the extraction within a single pump flash of a sequence ofQ‐switched pulses with individually predetermined energies and spacings. Further, because the lowQstate of the resonator involves almost 100% round‐trip loss and no power to the deflector, high standoff capability and low‐rf‐power requirements are realized.

ISSN:0003-6951    

DOI:10.1063/1.1654081

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

We have made light‐guiding thin films with losses of ∼ 2.2 dB/cm at 0.633 &mgr;m from Kodak KPR photoresist which has been processed to remove a photosensitizer which absorbs in the visible. Curved and straight optical strip guides as narrow as 5 &mgr;m have been written in these films and have shown light guiding with losses of 3 to 8 dB/cm at 0.633 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.1654082

出版商:AIP    

年代:1972

数据来源: AIP