We report a simple fiber-implemented technique for complete reconstruction of intensity profile and phase of ultrashort laser pulses based on processing only pulse spectrum and two self-phase modulated spectra measured after a short piece of optical fiber. Its applicability is shown on an example of a fiber optical system in the telecommunication range. A retrieval algorithm in a dispersionless approximation and with considering dispersion effects is developed. The obtained results are confirmed by measurements using the second-harmonic generation frequency-resolved optical gating technique and by reconstructing purposely introduced signal features. We also provide estimates demonstrating great opportunities for implementing this technique in all-waveguide optical systems ranging from optical communications to nanophotonics with femtojoule pulses as well as to mid-IR photonics, where specialty fibers with huge optical nonlinearities can be used.

We report novel functionalities of a very simple, robust, and low-cost optical metrology method for the reconstruction of an intensity profile and phase of pulses in the telecommunication range based on measuring the fundamental spectrum and two self-phase modulated spectra after a nonlinear element with Kerr nonlinearity. We demonstrate, for the first time, to the best of our knowledge, the possibility of implementing this method using a microstructured tellurite fiber (with a zero dispersion wavelength of 1.55 μm and nonlinear coefficient >500 (W km)-1) as a nonlinear element for characterizing optical pulses with a wide range of parameters: wavelengths from O-band to L-band, durations from <100 fs to ~100 ps, low energies (~100 pJ), and/or low peak powers (~1 W). The intensity and phase of 80-fs ultrashort pulses with an energy of ~100 pJ are retrieved experimentally. We give a detailed theoretical analysis of the possibilities of reconstructing telecommunication pulses, including the important problem of measuring two coherent neighboring pulses whose wings may overlap.

Erbium-doped high purity zinc-tellurite fiber lasers operating at 2.7-2.8 μm were demonstrated by pumping in the 980 nm Er ³⁺ absorption band. To the best of our knowledge, a maximum pulse energy of 500 μJ over ~100 μs duration with a slope efficiency of 5 % was achieved for the first time in a 50-cm TeO ₂ -ZnO-La ₂ O ₃ -Na ₂ O-Er ₂ O ₃ glass fiber containing 2.5 mol % Er ₂ O ₃ . Lasers operating at 2.7 μm and 2.8 μm were also demonstrated with 35-cm and 70-cm gain fibers, respectively, but with lower slope efficiencies. For pumping Er ³⁺ -doped zinc-tellurite fibers, we used a low-cost high efficiency diode laser at 976 nm, which already provides an opportunity to implement the milliwatt level of a fiber laser of practical interest.

This paper presents an experimental study of broadband mid-IR amplification that is carried out, for the first time, to the best of our knowledge, in an erbium-doped tungsten tellurite fiber. A simple, robust supercontinuum source based on a tapered germanate fiber is developed as a seed input in the region of 1.5–3 µm. We show that gain by a factor of 5 on one pass can be achieved in the 2.7 µm range by pumping a low-cost, high-efficiency diode laser at 976 nm using high-purity tellurite glass fibers.