Theoretical investigation of a tunable external cavity diode laser based on a single cavity all-dielectric thin-film Fabry–Perot filter

Abstract

The single cavity all-dielectric thin film Fabry–Perot filter (s-AFPF) has been theoretically investigated in this paper as a means of tuning the wavelength in an external cavity diode laser (ECDL), and the means of limiting longitudinal mode hopping has been also theoretically investigated. When a TE or TM plane wave irradiates an s-AFPF, a quasi-linear relationship is found in a certain wavelength range between the optical intensity peak transmittance wavelength of s-AFPF and the cosine value of plane wave incident angle at s-AFPF. Based on this feature, we proposed and theoretically investigated an ECDL configuration based on an s-AFPF. By theoretical calculation, the actuator flat edge against the steel ball may be replaced by a bent edge to convert the mode-hop wavelength region into mode-hop-free wavelength region. The ECDL can be used in the application of environmental monitoring, atomic and molecular laser spectroscopy research, precise measurements, and so on.