Photonic Device Design Based on BBO for Ultrafast Frequency Doubling

Group velocity mismatch becomes the main obstacle for frequency conversion of ultrashort pulses due to dispersion. To solve the problem, one design is proposed for group velocity compensated second harmonic generation in a periodically modulated BBO crystal structure: the α-BBO/β-BBO multi-layer microstructure. The results show that the device can be well applied from the visible red to the near infrared region.