A novel tuning method for a ring-cavity THz-wave parametric oscillator

Summary form only given. We describe a ring-cavity THz-wave parametric oscillator that uses a novel frequency tuning control method, which involves rotation of a single mirror of the idler resonator. In this way, optical alignment of pump beam and idler beam can be facilitated since the fixed pump path suppress optical damage of a nonlinear crystal edge and the idler path is automatically aligned in order to satisfy the appropriate noncollinear phase matching condition, respectively. Another advantage lies in the fact that an enhanced tuning response can be achieved by using a high-response scanner, such as a galvanometer scanner.