Raman spectroscopy with laser frequency combs

Advances in optical spectroscopy and microscopy have had a profound impact throughout the physical, chemical and biological sciences. Particularly valuable are label-free methods capable of probing complex systems in a non-destructive and chemically sensitive manner, ideally with high spatial and temporal resolution. This is offered by coherent Raman spectroscopy, and here Takuro Ideguchi et al now show that it can be implemented using two laser frequency combs and thereby allow spectra covering a wide bandwidth to be measured with high resolution on a single detector on the microsecond timescale. With further system development, the method is expected to offer exciting new possibilities not only in spectroscopy but also for real-time microscopy observations of, for example, biological processes.