Dye-doped polystyrene laser
doi:10.1038/nindia.2012.46 Published online 30 March 2012
New research has shown laser-like emission from three-dimensional self-assembled photonic crystals containing dye-doped nanospheres made of polystyrene. Such dye-doped solid photonic crystals could be used as solid nanophotonic laser sources in optical circuits.
Photonic crystals made from zinc oxide have been shown to exhibit photonic-band-edge lasing at near-ultraviolet wavelengths. However, making such crystals requires complex steps and yields very small sample sizes. To design quick-to-fabricate and large laser-light-emitting photonic crystals, the researchers prepared photonic crystals on a clean substrate using colloidal suspensions of rhodamine-B-doped polystyrene.
The researchers irradiated the crystals with visible laser light. When the light excited a source inside the photonic crystal, the emitted light was diffuse and propagated in all directions except in the stop gap direction. The researchers found that more photons were emitted on the blue side of the stop gap when the emission was suppressed within the stop gap.
The lasing was due to the enhancement of emission near the band edges of the photonic crystal. The researchers say that the enhancement of emission at certain frequencies can be further exploited for use in solid-state lighting devices.
- Nair, R. V. et al. Photonic-band-edge-induced lasing in self-assembled dye-activated photonic crystals. Phys. Rev. A 85, 023844 (2012)