Passively mode-locked laser with an ultra-narrow spectral width

Kues, M., Reimer, C., Wetzel, B., Roztocki, P., Little, B. E., Chu, S. T., Hansson, T., Viktorov, E. A., Moss, D. J. and Morandotti, R. (2017) Passively mode-locked laser with an ultra-narrow spectral width. Nature Photonics, 11(3), pp. 159-162. (doi: 10.1038/nphoton.2016.271)

Abstract

Most mode-locking techniques introduced in the past1, 2 focused mainly on increasing the spectral bandwidth to achieve ultrashort, sub-picosecond-long coherent light pulses. By contrast, less importance seemed to be given to mode-locked lasers generating Fourier-transform-limited nanosecond pulses, which feature the narrow spectral bandwidths required for applications in spectroscopy3, the efficient excitation of molecules4, sensing and quantum optics5. Here, we demonstrate a passively mode-locked laser system that relies on simultaneous nested cavity filtering and cavity-enhanced nonlinear interactions within an integrated microring resonator. This allows us to produce optical pulses in the nanosecond regime (4.3 ns in duration), with an overall spectral bandwidth of 104.9 MHz—more than two orders of magnitude smaller than previous realizations. The very narrow bandwidth of our laser makes it possible to fully characterize its spectral properties in the radiofrequency domain using widely available GHz-bandwidth optoelectronic components. In turn, this characterization reveals the strong coherence of the generated pulse train.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Kues, Dr Michael
• Authors: Kues, M., Reimer, C., Wetzel, B., Roztocki, P., Little, B. E., Chu, S. T., Hansson, T., Viktorov, E. A., Moss, D. J., and Morandotti, R.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Nature Photonics
• Publisher: Nature Publishing Group
• ISSN: 1749-4885
• ISSN (Online): 1749-4893
• Published Online: 23 January 2017
• Copyright Holders: Copyright © 2017 Macmillan Publishers Limited, part of Springer Nature
• First Published: First published in Nature Photonics 11(3): 159-162
• Publisher Policy: Reproduced in accordance with the publisher copyright policy