Electromagnetically induced transparency in hydrogen as a Lyman-alpha spectral filter

Electromagnetically induced transparency (EIT) is a well explored area of physics with many diverse applications, including creating narrow spectral features in a thermal cloud of atoms. We simulate EIT in thermal atomic hydrogen in order to explore its efficacy as a narrow-band spectral filter for Lyman-alpha radiation produced by an intense discharge lamp [1]. The analysis focuses on the frequency-up-conversion regime [2, 3] where, unlike typical EIT set-ups with near equal laser wavelengths, the probe wavelength is much shorter than the drive wavelength. In our simulations, the EIT features are produced with an intense standing-wave field nearly resonant with either the 2P-3D or 2P-4D transitions. We find that EIT features with ~200 MHz widths are likely achievable with a carefully designed experimental setup and consider the implications for Doppler cooling atomic hydrogen with spectrally filtered light.