High frequency wavelength modulation spectroscopy with diode lasers

Compact stabilized semiconductor laser for frequency metrology

“…Semiconductor lasers are attractive for these applications, [15][16][17][18][19] especially where compact spectroscopy systems are desired. Diode lasers are available at many optical wavelengths and are directly tunable/ditherable via either modulation of their injection current or thier temperature.…”

Optical saturation effects in intracavity Faraday modulation spectroscopy (INFAMOS)

“…Trace gas detection using the Faraday effect can employ both static and modulated magnetic fields, with the latter providing the benefit of detection at higher frequencies and hence the rejection of low frequency noise. This modulation scheme is similar to the one in wavelength modulation spectroscopy (WMS) 34 but instead relies on the modulation of the optical transitions as opposed to the laser frequency. The intensity of the Faraday modulation signal measured at the first harmonic by a lock-in amplifier is proportional to the first Fourier coefficient of the Fourier representation of the now time dependent and periodic birefringence and dichroism.…”

Nonphotochemical hole burning of organic dyes and rare earth ions in polymers and glasses: a probe of the amorphous state

“…[81] and Pokrowsky et al [125] with the sophisticated detection tech nique of frequency modulation (FM) spectroscopy (vide supra). However, materials requirements are a much more difficult problem [125]. Several properties need to be satisfied: (1) reversible hole burning, (2) long lifetime holes, and (3) fast burning times (30 ns/bit).…”

“…Several properties need to be satisfied: (1) reversible hole burning, (2) long lifetime holes, and (3) fast burning times (30 ns/bit). Each of these properties have been accomplished in different materials, but to achieve all three simultaneously has yet to be accomplished for single-photon hole burning processes [124,125]. However, one possible solution is photon-gated hole burning (vide supra) which offers enhanced abilities since holes can be burned and probed nondestructively [20,96].…”