Possibility of CO2 Laser Pumped Terahertz Sources

Terahertz generation in nonlinear optical media is known to be a widely used way to generate single cycle terahertz pulses with great efficiency. Using high pumping intensity in semiconducting materials at the near infrared region is not feasible due to the strong multiphoton absorption [1]. As of now, carbon-dioxide lasers with 2 ps pulse durations are available [2], which can eliminate low-order multiphoton absorption due to their long central wavelength (approximately 10 $\mu \mathrm{m}$ ).