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1.
We describe the design, construction and first experimental results with an open triangle FIR ring resonator with Michelson interferometer output coupling, which we combined with a Brewster-windowless 10W CO2 pump laser to a compact laser package of 1m length. The achieved stability of power and frequency of this system is very high, typically on the order of ±0.01% over several hours and <20kHz per hour at 800GHz. For the design, we investigated the balance of all laser processes and determined the optimum dimensions for the open resonator cavity. This analysis is based on a radially homogenous overall laser model, including commonly accepted simplified rate equations together with molecular parameters for weak FIR laser lines. In accordance with the modelling the efficiency on the very most prominent lines is better than with conventional waveguide lasers, giving up to 4 times better efficiencies especially on lines with low absorption pump transitions. Several laser lines, however, have substantially enhanced pump thresholds on purely copropagating emission, suppressing laser operation below about 10W pump power threshold. We show that this can not be due to effects from the interferometer. 相似文献
2.
G. Carelli N. Ioli A. Moretti G. Moruzzi D. Pereira F. Strumia 《International Journal of Infrared and Millimeter Waves》1991,12(5):449-471
We have increased the frequency tunability of our CW waveguide CO2 lasers by means of an acoustooptic amplitude modulator, operating at the fixed frequency of 90 MHz. The up-shifted, or down-shifted, laser optical sideband can be generated independently by adjusting the orientation of the modulator. The efficiency is larger than 50%. The frequency tunability of the CO2 laser around each laser line is thus increased by 180 MHz. To demonstrate the possibilities of this method, a source composed of the above modulator and of a CW, 300 MHz tunable waveguide CO2 laser has been used for the search of new large offset FIR laser lines from optically pumped CH3OH and13CH3OH molecules. As a result 15 and 10 new large offset laser lines were discovered respectively. New assignments of some laser lines are also proposed. We have also measured the Stark effect, the offset, and the polarization of other already known lines. In particular a Stark effect frequency tuning of about 1 GHz is demonstrated for a laser line at 208.399 m. 相似文献
3.
T. George S. Saupe M. H. Wappelhorst W. Urban 《Applied physics. B, Lasers and optics》1994,59(2):159-166
We present a very high-resolution heterodyne spectrometer based on a CO laser which operates down to fundamental-band transitions of the molecule. This allows us to detect saturated absorption signals on these transitions at very low pressure (0.4 Pa) and laser intensity (< 1 mW/cm2), yielding a linewidth of about 250 kHz. With the CO fundamental-band laser stabilized to these saturation signals we have measured the transition frequencies of the fundamental bands of three isotopic species to an accuracy of typically 20 kHz (v/v 3 × 10–10), referenced to the CO2 frequency standard. Together with additional frequency measurements of the first hot bands, these provide the first heterodyne frequency data of sub-Doppler accuracy for transitions in low lying bands of CO. They now represent the most accurate secondary frequency standard in the spectral region around 5 µm (60 THz). 相似文献
4.
I. Mukhopadhyay R. M. Lees W. Lewis-Bevan J. W. C. Johns F. Strumia G. Moruzzi 《International Journal of Infrared and Millimeter Waves》1987,8(11):1483-1502
High-resolution infrared (IR) and far infrared (FIR) Fourier transform absorption spectra have been employed to investigate assignments of FIR laser lines reported from optically-pumped13CH3OH. The spectroscopic measurements are used in conjunction with the reported IR pump and FIR laser frequencies to form closed combination loops for several systems, serving to confirm the assignments and in some cases to improve the accuracy of the FIR laser frequencies. Frequency predictions from combination differences are also presented for a number of potential new FIR laser lines. 相似文献
5.
We report an efficient operation of a kilohertz nanosecond extracavity KGd(WO4)2 (KGW) crystal Raman yellow laser, which is pumped by a 532 nm lasers based on pulse laser diode (LD) side-pumped ceramic
Nd: YAG, BBO electro-optical Q-switched and LBO crystal extracavity frequency doubling. With the 5 W, 10 ns and 1 kHz output
power pumped at 532 nm, we obtained 2.58 W, 7.4 ns, 1 kHz second Stokes Raman laser output at 579.54 nm for 768 cm−1 Raman shift of KGW crystal, corresponding to a conversion efficiency of 51.4%. By changing the KGW crystal orientation, we
further obtained 3.18 W, 7.8 ns, 1 kHz Raman pulses at 588.33 nm for 901 cm−1 Raman shift, corresponding to a conversion efficiency of 63.3%. The beam quality factors M2 of 579.54 and 588.33 nm were (M
x−579.542 = 5.829, M
y−579.542 = 6.336) and (M
x−588.332 = 6.405, M
y−588.332 = 6.895), respectively. 相似文献
6.
Yang Tan Qing‐Fang Luan Feng Chen Daniel Jaque Javier Rodríguez Vázquez de Aldana 《固体物理学:研究快报》2013,7(11):1018-1021
Violet, blue, and green lasers were simultaneously generated by nonlinear processes using ultrafast laser inscribed neodymium‐doped yttrium aluminum borate (Nd:YAl3(BO3)4 or Nd:YAB) channel waveguides under pumping at 815 nm. These visible lasers were generated by the frequency doubling, self‐frequency summing, and self‐frequency doubling processes based on a 1062 nm laser radiation that corresponded to the 4F3/2 → 4I11/2 transition of Nd3+ ions. Further, the wavelength tunability for the violet and blue lasers was achieved by simply tuning the pump wavelength within the 4I9/2 → 4F5/2 transition. The results obtained indicate that Nd:YAB waveguides are promising candidates for efficient compact visible laser sources. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
7.
The absolute frequency of an iodine-stabilized He-Ne laser at 633 nm stabilized on the i (or a13) component of the 11-5 R(127) hyperfine transition of the 127I2 molecule is measured using a femtosecond optical comb generator and an iodine-stabilized Nd:YAG laser standard at 1064 nm.
We link the measured absolute frequency to the current internationally adopted value via frequency intercomparison between
JILA and the Bureau International des Poids et Mesures (BIPM), leading to the determination of the absolute frequency of the
BIPM-4 standard laser. The resulting absolute frequency fi(BIPM) of the BIPM-4 standard laser is fi(BIPM)=473612214711.9±2.0 kHz, which is 6.9 kHz higher than the value adopted by the Comité International des Poids et Mesures (CIPM)
in 1997.
Received: 29 May 2000 / Revised version: 13 September 2000 / Published online: 22 November 2000 相似文献
8.
The methane E line at 2947.811 cm-1 has been observed by the saturated absorption technique using a Zeeman shifted 3.39 μm He-Ne laser. The frequency separation between this line and the F(2)2 line in methane, commonly used as an infrared frequency reference, is measured to be ν(F22) - ν(E) = 3032560 ± 5 kHz. It has been checked that the E line is free from power and Stark frequency shifts within our 5 kHz measurement precision. 相似文献
9.
Franck Bielsa Khelifa Djerroud Albane Douillet Tristan Valenzuela Christophe Daussy Anne Amy-Klein 《Journal of Molecular Spectroscopy》2008,247(1):41-46
We report on highly accurate absolute frequency measurement against a femtosecond frequency comb of six saturated absorption lines of formic acid (HCOOH) with an accuracy of 1 kHz. We also report the frequency measurement of 17 other lines with an accuracy of 2 kHz. Those lines are in quasi coincidence with the 9R(36) to 9R(42) CO2 laser emission lines and are probed either by a CO2 or a widely tunable quantum cascade laser phase locked to a master CO2 laser. The stability of HCOOH stabilized lasers is characterized by a fractional Allan deviation of 3.1 × 10−12 τ−1/2. They give suitable frequency references for Doppler-free two-photon spectroscopy. 相似文献
10.
Ronaldo Celso Viscovini Artemio Scalabrin Daniel Pereira 《International Journal of Infrared and Millimeter Waves》2000,21(4):621-632
In this work we present the results of an investigation about Doppler limited infrared absorbing transitions of the in-plane methyl-rocking and the asymmetric methyl deformation modes of 13CD3OD by means of optoacoustic detection. This is an alternative and attractive technique to be applied to this methanol isotopomer, in comparison to Fourier transform spectroscopy. In fact the contamination problem associated with the fast exchange of OD by OH in the molecule limits the use of the Fourier transform technique. Using a waveguide CO2 laser of 290 MHz tunability on each line we were able to observe 20 IR absorptions, most of them of large offset. The data will be useful in theoretical analysis of this molecule, as well as in the generation of FIR laser radiation in optically pumped molecular laser. 相似文献
11.
V. Petrov M. Cinta Pujol X. Mateos
. Silvestre S. Rivier M. Aguil R.M. Sol J. Liu U. Griebner F. Díaz 《Laser \u0026amp; Photonics Reviews》2007,1(2):179-212
High‐quality crystals of monoclinic KLu(WO4)2, shortly KLuW, were grown with sizes sufficient for its characterization and substantial progress was achieved in the field of spectroscopy and laser operation with Yb3+‐ and Tm3+‐doping. We review the growth methodology for bulk KLuW and epitaxial layers, its structural, thermo‐mechanical, and optical properties, the Yb3+ and Tm3+ spectroscopy, and present laser results obtained in several operational regimes both with Ti:sapphire and direct diode laser pumping using InGaAs and AlGaAs diodes near 980 and 800 nm, respectively. The slope efficiencies with respect to the absorbed pump power achieved with continuous‐wave (CW) bulk and epitaxial Yb:KLuW lasers under Ti:sapphire laser pumping were ≈ 57 and ≈ 66%, respectively. Output powers as high as 3.28 W were obtained with diode pumping in a simple two‐mirror cavity where the slope efficiency with respect to the incident pump power reached ≈ 78%. Passively Q‐switched laser operation of bulk Yb:KLuW was realized with a Cr:YAG saturable absorber resulting in oscillation at ≈ 1031 nm with a repetition rate of 28 kHz and simultaneous Raman conversion to ≈ 1138 nm with maximum energies of 32.4 and 14.4 μJ, respectively. The corresponding pulse durations were 1.41 and 0.71 ns. Passive mode‐locking by a semiconductor saturable absorber mirror (SESAM) produced bandwidth‐limited pulses with duration of 81 fs (1046 nm, 95 MHz) and 114 fs (1030 nm, 101 MHz) for bulk and epitaxial Yb:KLuW lasers, respectively. Slope efficiency as high as 69% with respect to the absorbed power and an output power of 4 W at 1950 nm were achieved with a diode‐pumped Tm:KLuW laser. The slope efficiency reached with an epitaxial Tm:KLuW laser under Ti:sapphire laser pumping was 64 %. The tunability achieved with bulk and epitaxial Tm:KLuW lasers extended from 1800 to 1987 nm and from 1894 to 2039 nm, respectively. 相似文献
12.
R. C. Viscovini A. Scalabrin D. Pereira 《International Journal of Infrared and Millimeter Waves》1996,17(11):1821-1838
In this work we present the results of an investigation about Doppler limited infrared absorbing transitions of the C-O stretching vibrational mode of13CD3OD by means of optoacoustic detection. This technique is an alternative, more sensitive and of higher resolution than the Fourier transform spectroscopy which is applied to this methanol isotopomer, due to the contamination problem associated with the fast exchange of OD by OH in the molecule. Using a waveguide CO2 laser of 290 MHz tunability on each line we were able to observe 69 absorptions, most of then of large offset. The data will be useful in theoretical analysis of this sample, as well as a guide in the search for new FIR laser lines. 相似文献
13.
M. P. Sassi F. Bertinetto A. Godone E. Bava 《International Journal of Infrared and Millimeter Waves》1985,6(7):629-633
The frequency of the RI(32) CO2 line has been measured with respect to a 3.39 m He22Ne laser stabilized to the F2
(2) P(7) transition in thev
3 band of CH4. The value obtained isv=29477160862±12 kHz, in good agreement with the only value reported in the literature. Using the available data of the RI(32)-RI(30) (difference) frequency, the following value can be derived for the RI(30) line: =29442483320±18 kHz. 相似文献
14.
D. Das A. Banerjee S. Barthwal V. Natarajan 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(3):545-552
We have developed a ring-cavity resonator that
can be used to measure the absolute frequencies of optical
transitions with an uncertainty below 40 kHz. The length
of the resonator is calibrated against a reference laser
locked to the D2 line of 87Rb, the frequency of
which is known with 6 kHz accuracy. We demonstrate the
power of this technique by measuring the absolute
frequencies of various hyperfine transitions in the D1
line of 133Cs. Our results agree with earlier
measurements using the frequency-comb technique, and have
similar accuracy. Measurement of the D1-line frequency
could lead to a more precise determination of the
fine-structure constant. We also report a precise value of
A=291.918(8) MHz for the hyperfine constant in the
6P1/2 state. 相似文献
15.
D. Leibfried F. Schmidt-Kaler M. Weitz T. W. Hänsch 《Applied physics. B, Lasers and optics》1993,56(2):65-70
We describe the theory and experimental realization of an ultrafast phase-matched electrooptic modulator, working with 486 nm light and a modulation frequency of 84 GHz. To achieve phase matching for arbitrarily high modulation frequencies the laser beam is guided with several internal total reflections along a zig-zag path through a LiTaO3 crystal. The method was studied experimentally with a 84 GHz modulator and a highly stable 486 nm dye laser. The maximum modulation index of this setup was about 5.0%. Beat signals between either the first- or the second-order sidebands and another laser were observed. This modulator was used to directly measure the 671 GHz 1S–2S isotope shift of hydrogen and deuterium with radio-frequency accuracy. 相似文献
16.
Chang L. Yang C. Pang Q. S. Ai Q. K. Chen L. Y. Chen M. Li G. Yang J. H. Ma Y. F. 《Laser Physics》2012,22(5):914-917
We report an 885 nm laser diode (LD) end-pumped high beam quality (M
x
2 = 1.322, M
y
2 = 1.235) electro-optical Q-switched Nd:YAG laser with TEM00-mode output for the first time. At the absorbed pump power of 59.5 W, a 22.7 W 1064 nm laser was achieved at 10 kHz repetition
rate with optical-to-optical efficiency of 38.1%. The maximum pulse energy and shortest pulse width were 5.1 mJ and 14.5 ns
at 2 kHz repetition rate, and the calculated peak power was 352 kW. 相似文献
17.
D. Dangoisse J. Wascat J. M. Colmont 《International Journal of Infrared and Millimeter Waves》1981,2(6):1177-1191
A large number of emissions is obtained in the submillimeter and near millimeter range with the (H2CO)3 laser optically pumped by a CO2 laser. A study of the microwave absorption spectrum of the molecule carried out simultaneously with the submm analysis allows us to assign six of the laser lines in thev
5 excited state of the molecule and to determine the rotational constants and vibrational energy ofv
5. 相似文献
18.
Adi Rahwanto Rintaro Nomura Norihiko Nishizawa Toshio Goto Masakazu Mori Kazuo Yamane 《Optical Review》1998,5(1):5-8
A new scheme of an amplitude modulated harmonically mode-locked Er-doped fiber ring laser is proposed, and the lasing characteristics are experimentally investigated. The transform-limited sech2 pulses at the repetition frequency of 1.64 GHz are stably generated. The pulse width and spectral bandwidth are independent of both the amplitude modulated (AM) modulation signal frequency and the AM modulation depth. 相似文献
19.
2 laser standards. Using this technique, we can tune the CO laser frequency with absolute frequency control within the gain
profile of each laser transition. The frequency uncertainty is smaller than 15 kHz, corresponding to Δν/ν=2.5×10-10. Moreover, we obtain a reduction of the CO laser linewidth by a factor of 2 down to 65 kHz, corresponding to a spectral resolution
of δν/ν=1×10-9. With this outstanding accuracy and resolution we studied the shape of saturation dips in rovibrational lines of CO and carbonyl
sulfide (OCS) at low pressure (<5 Pa). The self-pressure-broadening rate of CO was found to be γc=+83(7) kHz/Pa in this pressure region. This value is about four times higher than values resulting from previous measurements
at much higher pressures. To our knowledge the measurements described here are the first line-shape studies with sub-Doppler
resolution in the 5 μm spectral region.
Received: 4 November 1996 相似文献
20.
I. Mukhopadhyay R. M. Lees W. Lewis-Bevan 《International Journal of Infrared and Millimeter Waves》1988,9(6):545-553
An assignment is proposed for the strong 127.0 m far-infrared (FIR) line of13CD3OH known to be pumped with very high efficiency by the 10P(8) CO2 laser line. On the basis of spectroscopic clues derived from calculated molecular parameters and energies for13CD3OH, the 127 m line is identified as the (nK,J)=(116,17)(125, 16) transition, and its companion 462.8 m line as the (116,17)(116,16) transition. Proposed partial assignments and predictions are also discussed for a number of other FIR laser lines in13CD3OH, CD3OH, CD3OD, CH3OD, CH3OH and13CH3OH. 相似文献