Double-wavelength coherent perfect absorption laser in Thue-Morse PT-symmetric photonic crystals

• The wavelength of the CPA-LP is dependent on the Th-M sequence number, the incident angle and the gain-loss factor in a photonic crystal. • Double-wavelength CPA-LPs may be achieved with the same value of incident angle for a specific gain-loss factor. • Double-wavelength laser consequently is supported and the transmittance of the CPA-LPs is optional. Coherent perfect absorption laser points (CPA-LPs) are investigated in the Thue-Morse (Th-M) PT-symmetric photonic crystals. CPA-LPs are induced as incident light impinges perpendicularly upon the structure. The operating wavelengths of the CPA-LPs are dependent on the Th-M sequence number, the incident angle and the gain-loss factor of materials. Especially, two CPA-LPs may be achieved with the same value of incident angle for a specific gain-loss factor. Double-wavelength laser consequently is supported in this structure and the corresponding transmittance of the CPA-LPs is optional. An abrupt jump in the calculated reflection coefficient phase could be found at the CPA-LPs as well. This study may be helpful in potential applications for lasers and highly sensitive sensors.