Electrotunable Non-reciprocal Laser Emission from a Liquid-Crystal Photonic Device


  • This work is partly supported by the TIT-KAIST Joint Program, the JSPS Research for the Future program, a 21st century COE program, a Grant-in-Aid for Exploratory Research (16 656 023) from the Ministry of Education, Science, Sports, and Culture, and a NEDO (New Energy Technology Development Organization) grant (Project ID 04A24 509). We acknowledge Prof. T. M. Swager for kindly supplying the polymer dye material used.


A liquid crystal (LC) photonic device with an anisotropic optical heterojunction structure has been fabricated. The device has a phase-retarding nematic LC (NLC) layer sandwiched between two polymer cholesteric LC films with right-handed helices of different pitches. Electrotunable non-reciprocal light transmittance and unidirectional circularly polarized (CP) lasing emission have been successfully demonstrated for this device structure. Two left CP (LCP) lasing emission peaks are observed at the edges of the overlapping region between the two photonic bands in the structure and are shifted upon the application of a voltage. In contrast, a non-reciprocal right CP (RCP) lasing emission peak emerges at one of the band edges and diminishes upon the application of a voltage. These phenomena are interpreted based on the selective reflection of RCP light and the reorientation of the NLC molecules by the application of a voltage.