Femtometer-resolved simultaneous measurement of multiple laser wavelengths in a speckle wavemeter

Graham D. Bruce, Laura O'Donnell, Mingzhou Chen, Morgan Facchin, Kishan Dholakia

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)
11 Downloads (Pure)


Many areas of optical science require an accurate measurement of optical spectra. Devices based on laser speckle promise compact wavelength measurement, with attometer-level sensitivity demonstrated for single wavelength laser fields. The measurement of multimode spectra using this approach would be attractive, yet this is currently limited to picometer resolution. Here, we present a method to improve the resolution and precision of speckle-based multi-wavelength measurements. We measure multiple wavelengths simultaneously, in a device comprising a single 1m-long step-index multimode fiber and a fast camera. Independent wavelengths separated by as little as 1 fm are retrieved with 0.2 fm precision using Principal Component Analysis. The method offers a viable way to measure sparse spectra containing multiple individual lines and is likely to find application in the tracking of multiple lasers in fields such as portable quantum technologies and optical telecommunications.
Original languageEnglish
Pages (from-to)1926-1929
JournalOptics Letters
Issue number7
Early online date19 Mar 2020
Publication statusPublished - 1 Apr 2020


Dive into the research topics of 'Femtometer-resolved simultaneous measurement of multiple laser wavelengths in a speckle wavemeter'. Together they form a unique fingerprint.

Cite this