Band-gap-tailored random laser

Abstract

A band-gap-tailored random laser with a wide tunable range and low threshold through infrared radiation is demonstrated. When fluorescent dyes are doped into the liquid crystal and heavily doped chiral agent system, we demonstrate a wavelength tuning random laser instead of a side-band laser, which is caused by the combined effect of multi-scattering of liquid crystal (LC) and band-gap control. Through rotating the infrared absorbing material on the side of the LC cell, an adjustable range for random lasing of 80 nm by infrared light irradiation was observed.

Liquid crystal random lasers

“…There are various ways to achieve tunable LCRL, e.g., varying temperature, 24,25 voltage, [26][27][28][29][30] composition or cell thickness, 31,32 mechanical strain in cross-linked cholesteric LC elastomers, [33][34][35] or using reversible photochemical reactions. 36,37 Hu et al 38 reported a wavelength-tuned LCRL caused by the combined effects of multiple scattering and bandgap control of LCs. By rotating the infrared absorbing material on the side of the LC cell, the tunable random lasing wavelength range of the 80 nm RL from 500 to 700 nm under infrared light irradiation was observed.…”

“…Hu et al 38 reported a wavelength-tuned LCRL caused by the combined effects of multiple scattering and bandgap control of LCs. By rotating the infrared absorbing material on the side of the LC cell, the tunable random lasing wavelength range of the 80 nm RL from 500 to 700 nm under infrared light irradiation was observed.…”

From Single to Multi Mode Lasing: The role of materials revealed in optical simulations

“…The extra defects can also be introduced in polymer stabilized CLCs or polymer dispersed liquid crystals in which the droplets of CLC are embedded in polymer matrix or domains of CLCs are separated by the elements of polymer networks [17]. Lasing modes can be excited not only at the spectral edge of the SRB band but also inside it [18][19][20]. The defects and inhomogeneities can be created in CLC matrix by different means, for example by adding nanoparticles [18], large polymer molecules [19] or by fast temperature changes of CLCs leading to the appearance of disoriented domains [20].…”

“…Lasing modes can be excited not only at the spectral edge of the SRB band but also inside it [18][19][20]. The defects and inhomogeneities can be created in CLC matrix by different means, for example by adding nanoparticles [18], large polymer molecules [19] or by fast temperature changes of CLCs leading to the appearance of disoriented domains [20]. This type of lasing is referred as a random lasing [21], the type of lasing with emitted light forming a closed path due to multiple light scattering at optical inhomogeneities.…”

Replica Symmetry Breaking in FRET‐Assisted Random Laser Based on Electrospun Polymer Fiber

“…This cavity‐less feature enables the easy realization of RLs based on the various disorder systems, such as liquid crystal, thin polymer film, quartz tube, and polymer fiber . Moreover, due to the modifiability of RLs, many studies have been devoted to functionalize the RL systems with special characteristics such as multicolor emission and tunable lasing wavelengths . Wavelength‐tunable RLs recently have attracted intense interest, because they show great promise for various fields, from spectroscopy to photochemistry and medicine .…”