Investigation into simultaneous FIR laser emissions in CH2F2 using a homodyne detection system

High-resolution FTIR measurement of the 2ν8 band of methylene fluoride (CH2F2)

“…Ground-state constants of CH 2 F 2 are available from microwave [20] and sub-mm wave [21] measurements. These have been corroborated by extensive far-infrared measurement [22] and by ground-state combination differences from FTIR studies on the m 8 band [9].…”

“…There has been obvious interest in the high-resolution infrared spectrum of difluoromethane (CH 2 F 2 , HFC-32) [1][2][3][4][5][6][7] due to its importance as an efficient laser medium for generation of far-IR laser emission [8][9][10][11][12] optically pumped by CO 2 lasers. Other interest associated with the spectral studies of CH 2 F 2 in particular the region of 3000 cm À1 is due to the fact that the high-resolution studies provide important information on anharmonic coupling and the different types of Coriolis interactions among the various modes which in turn can be very useful in understanding the coupling mechanism responsible for intramolecular vibrational energy redistribution (IVR) [13,14].…”

Millimeter- and Submillimeter-Wave Spectrum of Methylene Fluoride-d2

“…We have undertaken a systematic study of the mm/submm spectra of the ground and v 4 ϭ 1 state, and the high-resolution FTIR spectra in the 9 -10 m region ( 3 , 5 , 7 , 9 , and 2 4 ). Although the main infrared absorption of the pump laser is expected to be associated with transitions in the 3 , 7 , and 9 bands, some absorption due to hot band transitions is to be expected from the low-lying 4 vibrational state which has about 8% population at room temperature. Therefore, as a first step, in the present paper we report the results of the mm/submm-wave measurements and analysis of the rotational spectra in the ground state and v 4 ϭ 1 state.…”

Millimeter- and Submillimeter-Wave Spectra of 13CD2F2

“…Due to the density of energy levels introduced by asymmetry (κ = ∼−0.9) and very strong absorption in the 10 µm region, optical pumping of CH 2 F 2 and CD 2 F 2 by CO 2 lasers is known to give rise to powerful sub-mm and far-IR laser emission in the region 100-400 µm (1)(2)(3)(4)(5)(6). 13 CH 2 F 2 has also been identified to be a good lasing gas and several sub-mm emissions have been reported (7).…”