Widely tunable external-cavity surface-emitting laser using various methods.

We report a widely tunable optically pumped vertical-external-cavity surface-emitting laser. The multiple quantum wells in the active region of the gain chip are generally designed to form the resonant periodic gain structure, and three different methods are used to tune the oscillating wavelength. The maximum wavelength coverage of 45 nm is obtained when a 2 mm thickness birefringent filter is introduced in a straight-line cavity, while the tuning range of 8 nm is performed by employing a 0.15 mm thickness uncoated Fabry-Perot etalon. For the first time, to the best of our knowledge, we present an 11 nm tuning range by the use of an inserted blade as the tuning element, and the related wavelength tuning mechanism is analyzed.