Fig.2From: Flexible minimally invasive coherent anti-Stokes Raman spectroscopy (CARS) measurement method with tapered optical fiber probe for single-cell applicationa Schematic diagram of the SSFS-based CARS system with composite wavelength tuning. LCVR: liquid crystal variable retarder, PBS: polarization beam splitter, HWP: half-wave plate, BE: beam expander, FP: fiber-port, PM-PCF: polarization-maintaining photonic crystal fiber, COL: collimator, SF10: SF10 dispersion glass rod, l1 = 5 cm, l2 = 15 cm, l3 = 15 cm, M: mirror, ODL: optical delay line, VA: variable optical attenuator, DM: long-pass dichroic mirror, SPF: short-pass filter, PMT: photomultiplier tubes. b Schematic diagram of the frequency difference tuning of the linearly chirped pump and Stokes pulse in spectral focusing by tuning relative time delayBack to article page