Coherent raman scattering
Label-free imaging with PICUS DUO
Coherent Raman scattering imaging (CRI), a chemically selective imaging technique, allows to visualize the distribution of different components in a sample. CRI uses two synchronized laser beams of different colors to probe the molecular vibrations in the sample and does not rely on labeling, e.g. with dyes. This label-free nature lead to its success within the biomedical field and is one of the main motivators for transitioning CRI into clinical settings. Our PICUS DUO is the ideal laser source for both implementations – coherent anti-Stokes Raman scattering (CARS) and stimulated Raman scattering (SRS) imaging – live and hyperspectral.
The SRS image besides highlights nuclei and cell bodies of MCF7 cells.
SRS IMAGING
WITH LOW-NOISE FIBER TECHNOLGOY
Based on Refined’s low-noise fi ber technology, the PICUS DUO allows sensitive multicolor SRS imaging. With a shot-noise limited RIN at -157dBc/Hz (Stokes output) across the complete tuning range, the PICUS DUO can compete with solid-state OPOs and offers several more fiber advantages.
OPTIMIZED FOR SRS IMAGING
- Stokes output shot-noise limited at 1 mA
- Integrated AM modulator
- Optimized low-noise detector available
SRS images of (left) mouse liver tissue, as well as (right) dermal structures, formed by lipids, in the skin of a mouse ear up to 60 µm deep.
CARS & SRS IMAGING
LIVE & HYPERSPECTRAL
Complex technical as well as biological samples contain a wealth of different components, each with a unique set of molecular vibrations. As the excitation wavelengths of our dual-color laser is tunable to a specific vibration within only 5 ms, live multicolor imaging of such samples becomes feasible. With such a tuning speed up to 100 user-selectable vibrational components could be imaged per second, assuming an equal time span for tuning and image acquisition. This is an important prerequisite for the application of CRI in time critical settings, such as operating theater or for multiple samples in large studies.
- Tuning between 700 and 3200 cm-1 in <100 ms
- No external delay required
- [100 spectral pts, 256*256 pxl, 10 us dwell time] in just 1 min
Live CARS imaging video of a technical sample containing three different chemical components. Each of the three images is acquired in 125 ms subsequently and the laser wavelength is changed between each image in 5 ms:
Live SRS imaging video of a sample containing deuterated DMSO and oil. Each of the two images is acquired in 125 ms subsequently and the laser wavelength is changed between 2125 wn and 2850 wn in a frame-by-frame manner in 5 ms:
