An Ultrafast Wideband Discretely Swept Fiber Laser

The wavelength sweeping technology has gained its popularity in various research areas for the high resolution and high throughput capabilities. Illuminating with continuously wavelength-swept spectra, traditional spectrally encoded optical systems show low detection sensitivities in either time or spectral domains, due to the optical power divergence. In addition, they can also deliver a nontrivial sampling rate when fast line scan is performed, easily go beyond 50 GS/s, which overwhelms the conventional data processing system. In this paper, we demonstrate a 15-MHz discretely swept source at a bandwidth of ~70 nm particularly for high-speed spectrally encoded applications. The wideband discretely swept laser exhibits higher peak power, which enhances the detection sensitivity of optical system by more than 3 dB. The discretely sweeping characterization of the proposed laser is also proved to have the potential of reducing the data stream for fast processing without compromising the line-scan rate. It is believed that the efforts made in this paper provide a promising resolution for in situ ultrafast optical diagnosis at a higher sensitivity.