title: Ultrafast pulse compression, stretching-and-recompression using cholesteric liquid crystals.
abstract: We have experimentally demonstrated the feasibility of direct compression, or stretching and recompression of laser pulses in a very wide temporal time scale spanning 10's fs to ~1 ps time with sub-mm thick cholesteric liquid crystal (CLC) cells. The mechanisms at work here are the strong dispersion at the photonic band-edges and nonlinear phase modulation associated with the non-resonant ultrafast molecular electronic optical nonlinearity. The observed pulse compression limit, spectral characteristics and intensity dependence of the compression are in good agreement with theoretical expectations and simulations based on a coupled-mode propagation model. Owing to the large degree of freedom to engineer the wavelength locations of CLC photonic bandgap and band-edges, these self-action all-optical processes can be realized with ultrafast lasers pulses in a very wide spectral region from the visible to near infrared, with potential applications in compact ultrafast photonic modulation devices/platforms.
authors.forename: Yikun
authors.initials: Y
authors.lastname: Liu
authors.forename: You
authors.initials: Y
authors.lastname: Wu
authors.forename: Chun-Wei
authors.initials: CW
authors.lastname: Chen
authors.forename: Jianying
authors.initials: J
authors.lastname: Zhou
authors.forename: Tsung-Hsien
authors.initials: TH
authors.lastname: Lin
authors.forename: Iam Choon
authors.initials: IC
authors.lastname: Khoo