Generation of time-multiplexed chiroptical information from multilayer-type luminescence-based circular polarization conversion films

Abstract

Circularly polarized (CP) light generated from photoluminescence (PL) has great potential for the transmission of diverse forms of optical information including light intensity (brightness), spectral profile (color), and polarization (left-handed (LH)/right-handed (RH)), as well as temporal information corresponding to the PL lifetime of the CP light source. However, a systematic approach to the design of CP light-generating materials for the conveyance of time-multiplexed chiroptical information has not yet been reported. Herein, we demonstrate a novel approach to time-multiplexing chiroptical information using multilayered luminescence-based CP convertors comprising two linearly polarized luminescence (LPL) films with different PL lifetimes and a quarter-wave retardation film. We prepared LPL films with short and long PL lifetimes by stretching films comprising poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and CdSe/CdS core/shell quantum rod (QR) luminogens, respectively. We then fabricated four types of multilayered luminescence-based CP convertors by laminating the LPL_MEH-PPV and LPL_QR films with quarter-wave retardation films, so that the azimuthal angles between the polarization axes of the LPL films and the fast axes of the quarter-wave films differed in each case. The resulting CP light comprised short- and long-lifetime components. Subsequently, we used a time-resolved spectroscopic technique to extract time-multiplexed chiroptical information from changes in the time-course of the spectral profile of the LH- and RH-CP light. The time-varying of CP light profiles were thereby read-out as time-multiplexed chiroptical information. Our findings will pave the way for the design of CP light-generating materials for conveying time-multiplexed chiroptical information.