Second Harmonic Generation in Polymer Photonic Integrated Circuits

• Published in: Journal of lightwave technology Vol. 39; no. 7; pp. 2123 - 2129
• Main Authors: Conradi, Hauke, Hakmi, Almontaserbillah, Kleinert, Moritz, Liebermeister, Lars, de Felipe, David, Weigel, Madeleine, Kresse, Martin, Zawadzki, Crispin, Globisch, Bjorn, Keil, Norbert, Freund, Ronald, Schell, Martin
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-04-2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Coherent radiation; Continuous wave lasers; Couplings; Crystals; Fourth harmonic generation; GRIN lenses; Integrated circuits; Integrated optics; Lasers; Lenses; Lithium niobates; nonlinear optics; Optical pumping; Optical waveguides; photonic integration; Photonics; polymer waveguides; Polymers; Second harmonic generation; third harmonic generation; Ultrafast optics; Waveguides
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2020.3046371

Second harmonic generation is an efficient way to create coherent radiation at wavelengths that are not accessible with standard laser sources. In this work we demonstrate second harmonic generation from 1550 to 775 nm in a polymer photonic integrated circuit via the hybrid integration of a periodically poled lithium niobate crystal. The bulk crystal is inserted in an on-chip free-space section between two waveguide coupled GRIN lenses. Fiber to fiber conversion efficiencies were 0.03%/W for a continuous wave laser source and 100%/W for a femtosecond laser source. Furthermore, third and fourth harmonic light at 517 and 388 nm was observed.