Browse - Applied Physics Letters

Select this Article

Electron density measurements in collision−dominated plasmas

T. V. George and L. J. Denes

Appl. Phys. Lett. 26, 1 (1975); http://dx.doi.org/10.1063/1.87973 (3 pages) | Cited 3 times

Online Publication Date: 2 September 2008

Show Abstract

A simple technique, based on the absorption of far−infrared radiation, is shown to provide direct electron number density data in atmospheric large−volume plasmas. Spatially and temporally resolved measurements of electron density were obtained from a 10−cm plasma over the range 10¹¹−3×10¹³ cm⁻³ using a 337−μm laser source. The measurement configuration allowed a 0.5−cm spatial resolution and a 200−nsec temporal resolution.

Show PACS

52.70.Kz	Optical (ultraviolet, visible, infrared) measurements
52.80.Hc	Glow; corona
42.60.Jf	Beam characteristics: profile, intensity, and power; spatial pattern formation

Select this Article

Thomson scattering from a CO₂−laser−heated magnetically confined plasma

J. S. Pearlman, Z. A. Pietrzyk, and G. C. Vlases

Appl. Phys. Lett. 26, 3 (1975); http://dx.doi.org/10.1063/1.87976 (3 pages) | Cited 12 times

Online Publication Date: 2 September 2008

Full Text: | Download PDF

Show Abstract

Measurements of the interactions of CO₂ laser radiation with a theta pinch plasma have been made using laser scattering as a diagnostic technique. The plasma was heated axially with a TEA CO₂ pin laser. The scattering measurements have shown the time evolution of the laser−heated plasma during and after heating by the ’’spike’’ of the CO₂ laser. The energies involved in the change of plasma conditions agree well with the theoretical absorption associated with the inverse bremsstrahlung mechanism.

Show PACS

52.50.Jm	Plasma production and heating by laser beams (laser-foil, laser-cluster, etc.)
52.70.Kz	Optical (ultraviolet, visible, infrared) measurements

Select this Article

Pressure coefficient of thermoelectric power of platinum/platinum−10% rhodium and Chromel/Alumel thermocouples

V. M. Cheng, P. C. Allen, and D. Lazarus

Appl. Phys. Lett. 26, 6 (1975); http://dx.doi.org/10.1063/1.87967 (2 pages) | Cited 24 times

Online Publication Date: 2 September 2008

Full Text: | Download PDF

Show Abstract

A differential measurement between two thermocouples of the same type, one under hydrostatic pressure and the other at zero pressure, was undertaken at temperatures up to 950 °C and pressures to 2 kbar, for platinum/platinum−10% rhodium (P/P10R) and Chromel/Alumel (C/A) couples, using an externally heated pressure cell. The correction term for P/P10R rises monotonically and levels off to a value of −0.44±0.02 °C/kbar at 800 °C. The correction term for C/A is in the opposite sense: it remains less than 0.1°C/kbar up to 450 °C where it begins to rise, eventually reaching 0.42±0.02 °C/kbar at 950 °C.

Show PACS

07.20.Dt	Thermometers
72.15.Jf	Thermoelectric and thermomagnetic effects
85.80.Fi	Thermoelectric devices

Select this Article

Optical waveguide of LiNbO₃ thin film grown by liquid phase epitaxy

Shintaro Miyazawa, Shoichi Fushimi, and Susumu Kondo

Appl. Phys. Lett. 26, 8 (1975); http://dx.doi.org/10.1063/1.87977 (3 pages) | Cited 20 times

Online Publication Date: 2 September 2008

Full Text: | Download PDF

Show Abstract

We report optical waveguiding of a LiNbO₃ single−crystal film grown onto a c−plate LiTaO₃ substrate by liquid phase epitaxy from a new Li₂O−V₂O₅ flux. A film of about 3−μm thickness supported seven TE and two TM modes. Measurements of the mode indices indicated that the film is a ’’uniform’’ waveguide having constant refractive indices n_o=2.288₄ and n_e=2.191₄ throughout the film. Attenuation was measured to be 5 and 11 dB/cm for TM and TE, respectively.

Show PACS

42.79.Gn	Optical waveguides and couplers
68.55.-a	Thin film structure and morphology

Select this Article

Growth strains and losses in Nb−diffused LiTaO₃ optical film waveguides

V. Ramaswamy and R. D. Standley

Appl. Phys. Lett. 26, 10 (1975); http://dx.doi.org/10.1063/1.87968 (3 pages) | Cited 9 times

Online Publication Date: 2 September 2008

Full Text: | Download PDF

Show Abstract

We have observed the formation of growth strains due to interfacial dislocations in thin films made by the diffusion of niobium into LiTaO₃. These dislocations become significant for films wherein Δn₀≳0.01; their effect is to increase the scattering loss of the optical guided waves in the film.

Show PACS

42.79.Gn	Optical waveguides and couplers
61.72.Lk	Linear defects: dislocations, disclinations

Select this Article

Influence of excited singlet absorption on output power of cw dye lasers

O. Teschke and A. Dienes

Appl. Phys. Lett. 26, 13 (1975); http://dx.doi.org/10.1063/1.87969 (3 pages) | Cited 8 times

Online Publication Date: 2 September 2008

Full Text: | Download PDF

Show Abstract

The effects of the absorption of the pump light by the first excited singlet state on the output of a Rhodamine 6G cw dye laser are investigated. Experimental results show a change in the incremental photon efficiency with pump wavelength. Theoretical expressions are derived for the output power, including the effects of excited state absorption. By matching experimental and theoretical results, values for the excited state absorption cross sections are found at four different wavelengths.

Show PACS

42.55.Mv	Dye lasers
31.50.Df	Potential energy surfaces for excited electronic states
32.80.Xx	Level crossing and optical pumping

Select this Article

Pulse generation in a cw dye laser by mode−locked synchronous pumping

J. M. Harris, R. W. Chrisman, and F. E. Lytle

Appl. Phys. Lett. 26, 16 (1975); http://dx.doi.org/10.1063/1.87970 (3 pages) | Cited 18 times

Online Publication Date: 2 September 2008

Full Text: | Download PDF

Show Abstract

A continuous train of <500 ps (detector limited) pulses has been produced with a cw dye laser pumped by a mode−locked argon ion laser. The cavity lengths of the dye laser and argon laser were made equal in order to synchronously amplify a single pulse oscillating in the dye laser. An intracavity acousto−optic modulator was used to dump dye laser pulses at rates as high as 10 MHz.

Show PACS

42.55.Mv	Dye lasers
32.80.Xx	Level crossing and optical pumping

Select this Article

Stimulated emission of cresyl violet pumped by N₂ laser or rhodamine 6G dye laser

Francesco Castelli

Appl. Phys. Lett. 26, 18 (1975); http://dx.doi.org/10.1063/1.87971 (2 pages) | Cited 1 time

Online Publication Date: 2 September 2008

Full Text: | Download PDF

Show Abstract

Cresyl violet solutions have been shown to lase when pumped with a N₂ laser or a rhodamine 6G dye laser. In the latter case the efficiency is much higher, and for appropriate solution concentrations the dye lases at the wavelength peak of its spontaneous emission. Under these conditions, the gain is so high that superradiance is obtained using only a 10−kW exciting pulse with 10% lasing efficiency.

Show PACS

42.55.Mv	Dye lasers
32.80.Xx	Level crossing and optical pumping
78.45.+h	Stimulated emission

Select this Article

Optical pumping and tunable laser spectroscopy of the ν₂ band of D₂O

F. Keilmann, R. L. Sheffield, J. R. R. Leite, M. S. Feld, and A. Javan

Appl. Phys. Lett. 26, 19 (1975); http://dx.doi.org/10.1063/1.87972 (4 pages) | Cited 14 times

Online Publication Date: 2 September 2008

Full Text: | Download PDF

Show Abstract

Absorption resonances in the ν₂ band of D₂O in near coincidence with CO₂ laser lines are reported and assigned. Optical pumping induces strong laser emission at new submillimeter wavelengths, confirming the assignments. Acousto−optic modulation is used to tune the R (22) line of the CO₂ laser into coincidence with the 000,5₃₃−010,4₂₂ D₂O transition. Its center frequency is 1079.8628 cm⁻¹; the linewidth (HWHM) due to collisional broadening is 13 MHz/Torr. D₂S and HDS transitions in near coincidence with CO₂ laser lines are also reported.

Show PACS

32.80.Xx	Level crossing and optical pumping
33.20.Ea	Infrared spectra
33.20.Fb	Raman and Rayleigh spectra (including optical scattering)
42.55.Lt	Gas lasers including excimer and metal-vapor lasers

Select this Article

High−sensitivity optical recording in KTN by two−photon absorption

D. von der Linde, A. M. Glass, and K. F. Rodgers

Appl. Phys. Lett. 26, 22 (1975); http://dx.doi.org/10.1063/1.87974 (3 pages) | Cited 55 times

Online Publication Date: 2 September 2008

Full Text: | Download PDF

Show Abstract

Birefringence changes are induced in a cubic potassium tantalate niobate crystal with an external electric field by two−photon absorption of picosecond optical pulses. The recording sensitivity of 100 μJ/cm² for elementary holograms with a few percent reconstruction efficiency is comparable to the sensitivity of holographic silver halide emulsions. The high sensitivity of KTN is shown to be due to efficient charge transport of photoexcited carriers.

Show PACS

42.30.-d	Imaging and optical processing
42.79.Vb	Optical storage systems, optical disks
42.40.Kw	Holographic interferometry; other holographic techniques
78.20.Fm	Birefringence