Electrically tunable fiber-integrated Yb-doped laser covering 74 nm based on a fiber Bragg grating array

摘要

Fiber lasers provide the foundation to combine an excellent beam quality in single mode operation with a robust and highly efficient design. Based on fiber-integrated configurations, they are employed in many different applications ranging from industry over research to medical technology. However, there is lots of potential to approach even new fields of applications e.g. in spectroscopy based on tunable systems with an adjustable emission wavelength. We present a novel tuning concept for pulsed fiber-integrated laser systems using an array of fiber Bragg gratings (FBGs) as discrete spectral filter. Based on stacking many standard FBGs, the bandwidth and filter properties are easy to scale by increasing the number of gratings allowing huge tuning ranges as well as tailored tuning characteristics. In this work, we demonstrate the potential of this electrically controlled tuning concept. Using an Ytterbium (Yb)-doped fiber laser, we investigate the general tuning characteristics. With variable pulse durations in the nanosecond regime, we demonstrate high signal contrast (～45 dB), excellent wavelength stability and narrow linewidth (＜15 GHz). In order to highlight the great spectral freedom, a tuning range of 74 nm in the Yb band is realized which, to the best of our knowledge, is the largest bandwidth reported based on a monolithic filter design.