Picosecond pulsed laser source with microchip‐based MOPA at 532 nm
Spectral line width < 0.1 nm
Pulse width < 100 ps
Repetition rate 40-50 kHz
Average output power 20-40 mW
The spectrometer consists of the detector and the spectrograph
Spectral resolution 10 cm-1
Raman shift range from 70 cm‐1 to 3100 cm-1
CMOS‐SPAD array chip with 128×8 identical active elements (SPADs), grouped together in quadruplets to form effectively 128×2 ”pixels” in the detector
Four (4) strictly adjacent time bins
The widths of the bins are separately programmable, from zero to a few nanoseconds
The set of time bins can be moved in time relative to the triggering laser pulse using the delay generator
The associated power supply, control, readout and timing electronics
PC with NI IO card
PC computer equipped with a National Instruments reprogrammable digital IO card. The control hardware system handles all time‐critical operations such as SPAD array control, readout and programming all delays (time bin widths and the master delay).
The measurement software collects raw spectra, which are combined and treated further in graphical user interface that is a Matlab‐based software.