The first decades of Doppler-free two-photon spectroscopy

Doppler - free two - photon spectroscopy in the vacuum ultraviolet : helium 11 S – 21 S transition

We describe techniques for laser spectroscopy in the vacuum-UV (VUV) spectral region that combine high spectral resolution with high absolute accuracy. A nearly transform-limited nanosecond laser source at 120 nm is constructed with difference-frequency mixing. This source is used to perform the first, to our knowledge, Doppler-free VUV measurement. We measure the inherently narrow 11S – 21S tw...

Doppler-Free Saturation Spectroscopy

Doppler-free Fourier transform spectroscopy.

Sub-Doppler broadband multi-heterodyne spectroscopy is proposed and experimentally demonstrated. Using two laser frequency combs of slightly different repetition frequencies, we have recorded Doppler-free two-photon dual-comb spectra of atomic rubidium resonances of a width of 6 MHz, while simultaneously interrogating a spectral span of 10 THz. The atomic transitions are uniquely identified via...

Sub-Doppler UV spectroscopy by resonance-enhanced two-photon ionization: the structure of the benzene20,22Ne cluster

In this work it is demonstrated that mass selected multiphoton ionization is a powerful technique for high resolution spectroscopy, isotope cluster separation and investigation of the structure of van der Waals clusters. The rotationally resolved UV spectra of the benzene-“Ne and benzene-**Ne clusters are selectively measured in a natural isotopic mixture of benzene and benzene-Ne clusters in a...

Two Photon Polarization Spectroscopy

2014 Dichroism and birefringence are studied for the case of a strong saturating laser and a linearly polarized weak probe laser interacting with a dilute gas. For linearly or circularly polarized saturating laser fields the optical analog of the Kerr or Faraday effect are obtained respectively. Two photon, Doppler-free polarization effects are studied for two and three level systems (J = 0 ~ J...