Design a type of tandem DBR that shows advantages over normal DBR in ultraviolet region.
The use of the tandem DBR (centered at 390 nm) enhances the extraction efficiency without detuning the cavity and meanwhile narrows the spectral width of the emitted light.
Demonstrate the potential that the tandem DBRs (centered at 343 nm and 246 nm respectively) have for enhancing the efficiency in deep UV device.