Band-edge-enhanced tunable random laser using a polymer-stabilised cholesteric liquid crystal

ABSTRACT

Electrically tunable random laser action has been demonstrated in a cavity-free structure. The scattering structure was shaped by the treatment of AC, and a polymer network structure is introduced to fix it. The fluorescence of the laser dye is scattered internally and selectively amplified at the band-edge of the photonic crystal, due to the concentrate of the photonic density of state. As the electric field increased, the deformation of the polymer network causes the cholesteric liquid crystal pitch to form a gradient distribution, resulting in the widening of the bandgap, and the random laser wavelength changes accordingly. This random laser with a broad tuning range (∼100 nm) opens new possibilities for the design of highly efficient incoherent light source in a large area with a thickness of micron level.

Graphical Abstract

KEYWORDS:

• Random laser
• photonic crystal
• PSCLC
• tunable laser
• speckle-free imaging

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

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Additional information

Funding

This work was supported by the National Natural Science Foundation of China [11874012,51573036]; Natural Science Foundation of Anhui Province [1708085MF150]; Distinguished Youth Foundation of Anhui Province [1808085J03]; Anhui Province Key Laboratory of Environment-Friendly Polymer Materials [KF2019001]; Fundamental Research Funds for the Central Universities [JZ2018HGPB0276,JZ2019HGPA0099,PA2020GDKC0009]; Southwest University of Science and Technology [19FKSY0111].