Study on application of wavelet denoising in Terahertz time-domain spectroscopy

It is an effective method to reduce the noise in signals by wavelet multi-scale decomposition. The keys of reducing noise in nonstationary signals are to select good mother wavelet and thresholds for each layer wavelet decomposition coefficients. In this paper, the wavelet analysis and wavelet de-noising are applied to analyse the data of Terahertz time-domain spectroscopy (THz-TDS). THz-TDS is the phase coherent electromagnetic radiate detection technique in nature, which can directly measures amplitude and phase of the THz radiation pulse simultaneously. The simulations are conducted about the applications of them in digital signal de-noising, and the results showed that the de-noising effect is improved. Meanwhile, after de-noising, the authors can not only improve the spectral revolution, but also get more spectral information.