Jarom Jackson

Laser wavelength metrology with color sensor chips.

We present a laser wavelength meter based on a commercial color sensor chip. The chip consists of an array of photodiodes with different absorptive color filters. By comparing the relative amplitudes of light on the photodiodes, the wavelength of light can be determined. In addition to absorption in the filters, etalon effects add additional spectral features which improve the precision of the device. Comparing the measurements from the device to a commercial wavelength meter and to an atomic reference, we found that the device has picometer-level precision and picometer-scale drift over a period longer than a month.

High-temperature calcium vapor cell construction and spectroscopy

We describe the construction, operation, and resulting spectroscopy of a high-temperature calcium vapor cell using the 657 nm intercombination transition in neutral calcium. Alkali contaminants inside the cell resulted in the emission of off-resonant fluorescence. The resulting lifetime of the 3P1 state in calcium atoms subjected to collisions with the contaminant vapor is quantified.

Light splitting with imperfect wave plates

We discuss the use of wave plates with arbitrary retardances, in conjunction with a linear polarizer, to split linearly polarized light into two linearly polarized beams with an arbitrary splitting fraction. We show that for non-ideal wave plates, a much broader range of splitting ratios is typically possible when a pair of wave plates, rather than a single wave plate, is used. We discuss the maximum range of splitting fractions possible with one or two wave plates as a function of the wave plate retardances, and how to align the wave plates to achieve the maximum splitting range possible when simply rotating one of the wave plates while keeping the other one fixed. We also briefly discuss an alignment-free polarization rotator constructed from a pair of half-wave plates.