Development of sensitive electric-field measurement method via electric-field-induced coherent anti-Stokes Raman scattering*

Electric fields in plasmas play key roles both in their physics and chemistry, and therefore electric field measurement is crucial for various applications to highly understand and control plasmas.

Recently we have reported the field measurement method via electric-field-induced coherent anti-Stokes Raman scattering (ECARS) in visible region (ECARSv) [1]. ECARSv is one of the nonlinear optical effect similar to ECARS in infrared region (ECARSi) [2] and electric-field-induced second harmonic generation (EFISH) [3]. The characteristics of ECARSv is the possibility of high sensitivity because of the efficient signal generation by vibrational resonance with probe molecules and signal generation in visible region which can be detected by sensitive photodetector such as photomultiplier tube. We have succeeded in detecting electric field in atmospheric pressure and room temperature hydrogen down to 0.5 V/mm, which is improved by an order of magnitude from that demonstrated by ECARSi [2] and EFISH [3]. The details of ECARSv demonstration and the possibility of further improvement will be presented.

[1] T. Koike et al., Phys, Rev. Lett. (in press).

[2] O. A. Evsin et al., Quantum Electron. 25 (1995) 278.

[3] B. M. Goldberg  et al., Appl. Phys. Lett. 112 (2018) 064102.