Optical Rotation Quasi-Phase-Matching for Circularly Polarized High Harmonic Generation

The first scheme for quasi-phase-matching high harmonic generation of circularly polarized radiation is proposed: optical rotation quasi-phase-matching (ORQPM). In ORQPM propagation of the driving radiation in a system exhibiting circular birefringence causes its plane of polarization to rotate; by appropriately matching the period of rotation to the coherence length it is possible to avoid destructive interference of the generated radiation. It is shown that ORQPM is approximately 5 times more efficient than conventional QPM, and half as efficient as true phase-matching.