These days, identifying cancerous tissue within the body requires a biopsy and a review of the extracted sample in a pathology lab. A team of German scientists have been working toward a way of spotting tumors using an endoscopic approach that doesn’t involve actually having to take samples. They’ve developed a multi-modality laser-based imaging probe that is capable of differentiating tissue types without requiring the use of a staining dye.
The probe is 8 mm in diameter and relies on extremely fast near-infrared lasers that can create “nonlinear optical effects” within targeted tissue. Three imaging methods are used simultaneously, namely coherent anti-stokes Raman scattering, second harmonic generation, and two-photon excited auto-fluorescence.
Each type modality is delivered to the tip of the probe separately channel thanks to a multi-core optical fiber. Moreover, because there are thousands of individual optical channels, the device is able to scan across a surface without relying on moving mirrors or other mechanical parts having to be integrated into its tip. The actual moving parts are located at other end of the optical fibers, allowing the tip to remain small.
The light from the lasers is focused using a novel lens, only 1.8 mm in diameter, that shapes the light thanks to a material that has a refractive index gradient throughout it.
Here’s a demo of the new probe in action:
Study in Optica: Endoscopic fiber probe for nonlinear spectroscopic imaging……
Via: The Optical Society…