Low-threshold and narrow linewidth diffusive random lasing in rhodamine 6G dye-doped polyurethane with dispersed ZrO_2 nanoparticles

Abstract

We report on low-threshold and narrow linewidth intensity feedback random lasing in Rhodamine 6G dye-doped polyurethane with dispersed ZrO2 nanoparticles. Depending on the dye/particle concentration, the lasing threshold is (6.8-15.4) MW/cm 2 and the linewidth is (4-6) nm. The lasing threshold as a function of nanoparticle concentration is found to follow a power law with an exponent of −0.496 ± 0.010, which is within uncertainty of Burin et.al.'s theoretical prediction [1].

Random lasing and reversible photodegradation in disperse orange 11 dye-doped PMMA with dispersed ZrO2nanoparticles

“…These large lasing thresholds are due to DO11 having a smaller gain coefficient than R6G [47,48,77] as well as our use of off resonance pumping (λ pump = 532 nm and λ res = 470 nm). Based on the observed lasing thresholds -and the observation that the 1.0 wt% sample didn't lase even with a pump energy of 60 mJ (I = 754 MW/cm 2 ) -we find that the RL threshold of DO11+ZrO 2 /PMMA increases with dye concentration, which is counter to measurements in other dyes [34]. One possible explanation for this effect is the formation of dimers at higher concentrations.…”

“…From Figure 5 we find that the linewidth changes from 100 nm at 5 mJ to 10 nm at 25 mJ and the intensity's slope only increases by a factor of ≈ 2.7×. This more gradual transition into lasing suggests that there is more competition between ASE and lasing [74,75] [5] or a bilinear fit to the peak intensity [34,76] of 75.8 ± 9.4 MW/cm 2 and the 0.5 wt% sample having a threshold of 121.1 ± 2.1 MW/cm 2 . Note that these thresholds are much larger (≈ 10×) than similar RL materials based on R6G [34].…”

“…This more gradual transition into lasing suggests that there is more competition between ASE and lasing [74,75] [5] or a bilinear fit to the peak intensity [34,76] of 75.8 ± 9.4 MW/cm 2 and the 0.5 wt% sample having a threshold of 121.1 ± 2.1 MW/cm 2 . Note that these thresholds are much larger (≈ 10×) than similar RL materials based on R6G [34]. These large lasing thresholds are due to DO11 having a smaller gain coefficient than R6G [47,48,77] as well as our use of off resonance pumping (λ pump = 532 nm and λ res = 470 nm).…”

“…Also, the limited number of active modes in RFRL allows for a high degree of spectral control, as the pump beam can be modulated using a spatial light modulator (SLM) to activate only certain lasing modes, thus controlling the RFRL spectrum [8,[27][28][29][30][31][32][33]. This spectral control is attractive for implementing optically based physically unclonable functions [34][35][36] and the creation of bright tunable light sources [8].…”

Random laser emission at dual wavelengths in a donor-acceptor dye mixture solution

“…Along with promising ideal illumination source other applications of RL are micro-lasers, speckle-free laser imaging [11], spatial cross talk, time resolve microscopy [12], and cancer detection [13]. In last few years, RL has been demonstrated in rhodamine-6G dye doped polyurethane dispersed with ZrO 2 nanoparticles [14], in quantum dots deposited into micro-scale grooves on glass [15], in rhodamine-640 dye dispersed with silica nanoparticles [7], in ZnO powder produced by sol-gel technique [8], in dye embedded silica gel [16], in single crystalline synthetic opal infiltrated with dye [17], in cholesteric liquid crystal dispersed with silver nanoparticles and laser dye [18] and in rhodamine-B dye dispersed with titanium oxide nano-particles, nano-rods and nano-tubes [6]. Recent developments in this field are designs of multi-coloured RL system [19], tunable RL [20], FRET based RL [21][22][23] and plasmonic RL system [24].…”