Multiple-pass Raman gain cell

Trutna, W. R.; Byer, Robert L.

doi:10.1364/ao.19.000301

Cited by 174 publications

(48 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Raman shift of 354 cm-1 shifts the pump wavelength to a Stokes wavelength of 16.11 gm. To increase the small Raman gain at these long Stokes wavelengths, a Multi-Pass Cell (MPC) [4] was used. The MPC consisted of two spherical mirrors separated by 3.7 m in a near-concentrical, stable-cavity setup in which the pump and Stokes beams were focused at each pass with a confocal parameter of 72 cm.…”

Section: Methodsmentioning

confidence: 99%

“…In the seeded experiments, higher-order Stokes waves were not generated and, consequently, using also a circularly polarized pump beam, no anti-Stokes waves were generated since the circular polarization excludes Stokes-anti-Stokes coupling. The seed pulse at the Stokes-shifted frequency of the CO2 laser was generated in the same MPC by a Four-Wave Mixing (FWM) process, where the 1.064 gm fundamental of a Q-switched Nd:YAG laser and its Stokes-shifted frequency were mixed with the 10 gm pump wave [4]. Since the Stokes-shifted wavelength of the Nd:YAG pump is much shorter than the Stokes-shifted wavelength of the COz pump wave, the Stokes gain is approximately a factor 200 higher for scattering at 1 ~tm [4].…”

Section: Methodsmentioning

confidence: 99%

“…The seed pulse at the Stokes-shifted frequency of the CO2 laser was generated in the same MPC by a Four-Wave Mixing (FWM) process, where the 1.064 gm fundamental of a Q-switched Nd:YAG laser and its Stokes-shifted frequency were mixed with the 10 gm pump wave [4]. Since the Stokes-shifted wavelength of the Nd:YAG pump is much shorter than the Stokes-shifted wavelength of the COz pump wave, the Stokes gain is approximately a factor 200 higher for scattering at 1 ~tm [4]. Therefore, the scattering of the Nd:YAG pump wave resulted in the generation of many higher-order Stokes waves and, due to parametrical coupling, also anti-Stokes waves.…”

Section: Methodsmentioning

confidence: 99%

“…Therefore, the scattering of the Nd:YAG pump wave resulted in the generation of many higher-order Stokes waves and, due to parametrical coupling, also anti-Stokes waves. First Stokes generation at 1.1 ~tm occurred with 40% energy efficiency [4]. Using the conversion function for FWM derived by Bjorklund [5], a maximum seed power of approximately 5 x 10 .2 MW may be estimated for the pump powers used in the experiments.…”

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Threshold and conversion experiments on seeded stimulated Raman scattering

Heeman

Godfried²,

Witteman

1995

Appl. Phys. B

View full text Add to dashboard Cite

Abstract. High energy-conversion efficiencies in Stimulated Raman Scattering (SRS) are demonstrated both in experiments and by simulations for pump powers below SRS threshold. The scattering is induced by a short seed pulse at the Stokes frequency, the pulse width of which is much shorter than the pump pulse width and which is comparable with the medium's dephasing time. PACS: 42.50.Md; 42.55.Ye; 42.65.Dr In a Raman-active medium, high conversion efficiencies to the Stokes wave can be achieved by Stimulated Raman Scattering (SRS). Due to the low gain for scattering to Stokes waves in the infrared, high pump powers and long interaction paths are necessary. Additionally, when the scattering becomes transient for pump pulses with a pulse duration comparable to the medium's dephasing time, the Raman gain is further reduced. One method to overcome the low Raman gain is by seeding. The scattering is then made efficient by an initially applied Stokes field rather than started up from the Stokes-noise field. The seed power easily exceeds the Stokes-noise power by many orders of magnitude, and substantially lowers the gain necessary to obtain Stokes powers comparable to the pump power. In previously performed experiments [1], the conversion efficiency in transient scattering was increased by a seed pulse with a pulse duration comparable to that of the pump pulse. ExperimentsIn the experiments described in this paper, the SRS efficiency of a pump pulse in the infrared is increased by adding a seed pulse at the Stokes frequency which is much shorter than the pump pulse, while the medium's dephasing time is of the same order of magnitude as the seed pulse. It is demonstrated both in experiments and in simulations that this short seed pulse is able to induce SRS with high energy-conversion efficiency, where unseeded scattering would otherwise generate Stokes energies below detection levels.In these experiments, a 10.26 gm pump pulse from a TEA CO2 laser with a pulse width of 70 ns at half maximum and a pump energy in the gain-switched peak of maximum 1.4 J was scattered by SRS in para-hydrogen (p-H2). The pump beam was nearly TEM0o but the pulse shape generally showed small modulation due to mode beating. The So(0) rotational transition was used as the Raman transition. For this transition, the pressure dependence of the dephasing time T2 of the Raman polarizability can be expressed as T2 = (~Bp)-i with B = 97.3 MHz/bar [2] for pressures p, where the Raman line width is pressure broadened, i.e., for pressures above approximately 0.3 bar [3]. The Raman shift of 354 cm-1 shifts the pump wavelength to a Stokes wavelength of 16.11 gm. To increase the small Raman gain at these long Stokes wavelengths, a Multi-Pass Cell (MPC) [4] was used. The MPC consisted of two spherical mirrors separated by 3.7 m in a near-concentrical, stable-cavity setup in which the pump and Stokes beams were focused at each pass with a confocal parameter of 72 cm. In the MPC, the number of passes could be varied with an axially mounted rotatable perisco...

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Threshold and conversion experiments on seeded stimulated Raman scattering

Heeman

Godfried²,

Witteman

1995

Appl. Phys. B

View full text Add to dashboard Cite

show abstract

“…Design considerations and test results for a multiple-pass, optical-resonator Raman cell have been presented recently y Trutna and Byer [50].…”

Section: Stimulated Raman Scattering As a Wavelength Shifting Mechanismmentioning

confidence: 99%

Shipboard Visibility Measurement System Definition Study.

Dowling¹,

Rogne²

1982

View full text Add to dashboard Cite

Enhancement of sensitivity in high‐resolution stimulated Raman spectroscopy of gases: Applicaion to the 2ν₂ (1285 cm⁻¹) band of CO₂

Saint‐Loup

Lavorel

Millot

et al. 1990

J Raman Spectroscopy

View full text Add to dashboard Cite

The application of a multiplepass gas cell to quasi-cw stimulated Raman scattering is demonstrated to be a powerful method for significantly increasing the sensitivity. As a consequence, such a device offers the possibility of working in the 0.1-1 Torr pressure range for weak bands. As a striking example, experimental results are given for the Zv, band of CO, at 1285 cm-I. The band is almost completely resolved with a very good signal-to-noise ratio.The Raman frequencies and the collisional broadening coefficients are determined as a function of quantum number J. Moreover, the possibility of auto-stimulated Raman effect on CO, at moderate pressure via the sbarp v , band (1388 cm-') is demonstrated. The fust Stokes signal has been measured with a very narrow tine width.

show abstract

Multiple-pass Raman gain cell

Cited by 174 publications

References 29 publications

Threshold and conversion experiments on seeded stimulated Raman scattering

Threshold and conversion experiments on seeded stimulated Raman scattering

Shipboard Visibility Measurement System Definition Study.

Enhancement of sensitivity in high‐resolution stimulated Raman spectroscopy of gases: Applicaion to the 2ν₂ (1285 cm⁻¹) band of CO₂

Contact Info

Product

Resources

About

Multiple-pass Raman gain cell

Cited by 174 publications

References 29 publications

Threshold and conversion experiments on seeded stimulated Raman scattering

Threshold and conversion experiments on seeded stimulated Raman scattering

Shipboard Visibility Measurement System Definition Study.

Enhancement of sensitivity in high‐resolution stimulated Raman spectroscopy of gases: Applicaion to the 2ν2 (1285 cm−1) band of CO2

Contact Info

Product

Resources

About

Enhancement of sensitivity in high‐resolution stimulated Raman spectroscopy of gases: Applicaion to the 2ν₂ (1285 cm⁻¹) band of CO₂