An offset-locked He-Xe laser system for high resolution spectroscopy on H
2CO at 3.51μm, was constructed using a Stark shifted line. In this offset-locked laser system, a local oscillator laser which is necessary in conventional system can be eliminated, because reference laser is locked at offset-frequency. The frequency stability and tunable range of this system is σ=8.8×10
-14 (at τ=10s) and 12 MHz, respectively, where σ is the square root of Allan variance and τ is the sampling time. The performance of this offset-locked laser system satisfied the requirement for a light source of ultra-high resolution spectroscopy.
The pressure broadening coefficient of H
2CO was measured to be 56±7 kHz/mTorr, using present system.
Stark coefficient of H2CO at 3.51 μm was precisely measured using beat frequency between two stabilized He-Xe lasers. The electric dipole moment at ν
5=1 excited vibrational state was measured to be 2.288±0.005 D.
抄録全体を表示