Terahertz time domain spectral radiation and detecting device

The invention relates to a terahertz time domain spectral radiation and detecting device. In the terahertz time domain spectral radiation and detecting device, femto second laser which is emitted from a femto second laser device is divided into pump light and probe light. Furthermore the pump light and the probe light are transmitted in a hollow photonic crystal fiber. In the terahertz time domain spectral radiation and detecting device, through reasonably selecting central wavelength of a pulse which is output from the femto second laser device, a two-order fiber dispersion which is generated in transmission of a laser pulse in the hollow photonic crystal fiber is a negative value, and the two-order fiber dispersion is neutralized with a positive dispersion which is generated by an optical isolator, a beam splitter, etc. The terahertz time domain spectral radiation and detecting device prevents inconvenience and cost of grating or a pair of prisms for compensating the dispersion. Secondly, because the pulse is basically transmitted in the hollow photonic crystal fiber, the energy of the pulse with pulse width of dozens of femto seconds can reach several hundreds of nanojoules. Furthermore pulse width increase because of self phase modulation is prevented. A high-energy laser pulse is supplied for a terahertz radiation device and a detecting device.