Evaluation of a Hadamard-coded photodiode-array spectrometer under low illumination

Hadamard spectrometers are well known for their multiplexing and/or throughput advantages. Traditionally these instruments require moving entrance and/or exit masks. The performance of a breadboard photodiode-array Hadamard transform spectrometer with a stationary entrance mask is evaluated against the same instrument configured with a single entrance slit. The higher throughput of the multislit, no-moving-parts instrument has provided a higher signal-to-noise ratio over the single-slit spectrometer in low-illumination conditions. Sources of noise are examined for the single-slit and multislit Hadamard instruments, and improvements for future designs are suggested.