Liquid crystal cells for phase and group delay control of femtosecond pulses — Application to hyperspectral imaging

Abstract

In this paper, we propose to exploit the large and electrically controllable birefringence of nematic liquid crystals for precise control of the group and phase delays of femtosecond pulses. To that purpose, liquid crystals intrinsically present very interesting optical features: a much higher birefringence than crystals, together with the ability to change their optical properties through molecular reorientation in response to a low voltage or weak magnetic field. Liquid crystals have been extensively studied for light manipulation and control [1]. However, application to the manipulation of ultrashort pulses has been quite occasional so far. Apart from spectral or spatial shaping by spatial-light-modulators in the Fourier plane, only a very few studies report on the use of liquid crystals for direct manipulation of ultrafast pulses.