Design And Application Of The Terahertz Time-Domain Spectroscopy

THz time-domain spectroscopy(THz-TDS) is a very effective means of coherent detection, which has many important applications. But up to now, there is no instrumental products of ultrafast THz-TDS with high power in China. Aiming for realizing its high-power, compact and multifunction, we design the THz-TDS based on the PCF femtosecond amplification laser. Some research on the characteristics and applications of the THz-TDS have been done. The main works are classified as follows:1. The methods of THz wave generation and detection based on the femtosecond pulse is introduced. A brief review on the development of ultrafast THz-TDS is summed up.2. A high-power,compact and multifunctional THz-TDS, which consists of the PCF femtosecond laser, THz emitter and detector, the data collection and process, and the electronic drive and control system, is designed and developed.3. Based on the delayer with high-speed translation stage, the rapid scan THz program is written. The influencing factors of the THz radiation SNR, such as the time constant and the speed of the delay line, are studied experimentally. A distinct improvement for the single scan speed is realized by the principle of selecting time constant.4. The developed THz-TDS is calibrated with the spectrum of lactose. The dielectric response of SBN:Ce ceremics modulating by a laser is investigated at room temperature by means of THz-TDS.