Ultrafast pulse generation in a mode-locked Erbium chip waveguide laser

Abstract

We report mode-locked ~1550 nm output of transform-limited ~180 fs pulses from a large mode-area (diameter ~50 μm) guided-wave erbium fluorozirconate glass laser. The passively mode-locked oscillator generates pulses with 25 nm bandwidth at 156 MHz repetition rate and peak-power of 260 W. Scalability to higher repetition rate is demonstrated by transform-limited 410 fs pulse output at 1.3 GHz. To understand the origins of the broad spectral output, the laser cavity is simulated by using a numerical solution to the Ginzburg-Landau equation. This paper reports the widest bandwidth and shortest pulses achieved from an ultra-fast laser inscribed waveguide laser.

Multimode Nonlinear Fiber Optics: Massively Parallel Numerical Solver, Tutorial, and Outlook

“…In hollow-core photonic crystal fiber, interactions between spatial modes have been used for phase-matching many unique processes [23], [64] however to date only fibers with a small number of modes have been considered. Waveguides written into planar or bulk media (fused silica, or SiN, for example) [65], [66] may also support a few or many spatial modes. Many microresonators (and "macro" resonators like Herriot cells [67], [68]) support multiple spatial modes, and the opportunities afford by multimode processes have just recently begun to be explored in these systems [69]- [73].…”

“…Recently, multimode effects are being explored in microresonators in the context of frequency combs [66], [69]- [73]. Multimode degrees of freedom allow qualitatively new kinds of solitons, which may allow for combs at different wavelength regimes, integrated dual comb functionality, compatibility with spatialdivision multiplexing, with higher conversion efficiency, and so on.…”

Self-corrected chip-based dual-comb spectrometer

“…WGLs thus seem to be an obvious choice for the centrepiece of a dual-comb platform. Figure 1 shows a schematic of the dual-comb spectrometer, whose design is inspired by the single-cavity mode-locked WGL presented in [28]. It revolves around a 13-mm-long ZBLAN glass chip containing several laserinscribed waveguides [32] with diameters ranging from 30 to 55 μm, which all support single-transverse-mode operation.…”

“…Two parallel waveguides having diameters of 45 and 50 μm are selected since we observe that they yield the best efficiencies as a result of a good balance between mode matching and pump confinement. The waveguides' large area ensures a low in-glass intensity, which increases the threshold for undesirable nonlinear effects [28].…”

“…In this paper, we present a standalone and free-running dual-comb spectrometer based on two passively modelocked waveguide lasers (WGLs) [28][29][30][31] integrated in a single glass chip. This mutually stable system allows to fully resolve the comb modes after using a new algorithm that corrects residual relative fluctuations estimated directly from the IGMs.…”