High signal to noise ratio THz spectroscopy with ASOPS and signal processing schemes for mapping and controlling molecular and bulk relaxation processes

摘要

Asynchronous Optical Sampling has the potential to improve signal to noise ratio inudTHz transient sperctrometry. The design of an inexpensive control scheme for synchronisingudtwo femtosecond pulse frequency comb generators at an offset frequency of 20 kHz isuddiscussed. The suitability of a range of signal processing schemes adopted from the SystemsudIdentification and Control Theory community for further processing recorded THz transients inudthe time and frequency domain are outlined. Finally, possibilities for femtosecond pulseudshaping using genetic algorithms are mentioned.