40-Channel, Boxcar-Integrator System for High-Resolution Pump-Probe Optical Spectroscopy

This work presents a multichannel platform specifically designed for broadband Pump-Probe spectroscopy, an advanced optical technique largely used in material science and biology to study ultrafast phenomena on the fs-ps timescale. While existing spectrometers are available on the market, they are constrained to operating with laser pulses in the tens of $\mathbf{k H z}$ range, leading to long acquisition times. This system aims to overcome these limitations exploiting a CMOS boxcar averager ASIC, which allows the use of lasers with a repetition frequency in the MHz range thanks to the switching capacitor technique. By reducing signal acquisition times exploiting faster lasers and the simultaneous acquisition of 40 wavelengths with parallel analog-digital signal processing, the platform achieves a 0.3 ppm resolution in 2 s acquisition time, better than current state-of-theart solutions.