Patent ID: 7953128

Claim:
A terahertz signal generation system, comprising: a first nonlinear difference frequency mixing (DFM) crystal stage for receiving pump radiation ω p1 and signal radiation ω s1 , and mixing ω p1 and ω s1 to generate terahertz radiation ω i1 ; a first optical parametric oscillator (OPO) crystal stage for receiving ω s1 as its pump radiation ω p2 , and generating signal radiation ω s2 and terahertz radiation having a frequency substantially equal to ω i1 ; a second nonlinear DFM crystal stage for receiving pump radiation ω p2 and signal radiation ω s2 , and mixing ω p2 and ω s2 to generate terahertz radiation ω i2 ; and a second OPO crystal stage for receiving ω s2 as its pump radiation ω p3 , and generating signal radiation ω s3 and terahertz radiation having a frequency substantially equal to ω i2 .