All-fiber femtosecond Cherenkov source

Abstract

Abstract. An all-fiber femtosecond Cherenkov radiation source is demonstrated for the first time, to the best of our knowledge. Using a stable monolithic femtosecond Ybdoped fiber laser as the pump source, and the combination of photonic crystal fibers as the wave-conversion medium, we have generated tunable Cherenkov radiation at visible wavelengths 580 -630 nm, with pulse duration of sub-160 fs, and the 3 dB spectral bandwidth not exceeding 36 nm. Such femtosecond source can find applications in practical biophotonics such as bio-imaging and microscopy.Many applications in biophotonics, such as multiphoton microscopy and ultrafast spectroscopy, require narrowband ultrafast (< 5 ps) pulses of a few milliwatts of average power that are tunable across the NIR, VIS, and UV spectral ranges [1,2]. In-fiber Cherenkov radiation (CR), also known as dispersive wave generation or nonsolitonic radiation, and originating from the perturbation of a stable temporal soliton by the higher-order fiber dispersion, can provide such a tunable output at multimilliwatt signal levels [3]. However, to the best of our knowledge, all the reported systems for femtosecond a e-mail: dmtu@fotonik.dtu.dk This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.