title: Vibrationally resonant sum-frequency generation microscopy with a solid immersion lens.
abstract: We use a hemispheric sapphire lens in combination with an off-axis parabolic mirror to demonstrate high-resolution vibrationally resonant sum-frequency generation (VR-SFG) microscopy in the mid-infrared range. With the sapphire lens as an immersed solid medium, the numerical aperture (NA) of the parabolic mirror objective is enhanced by a factor of 1.72, from 0.42 to 0.72, close to the theoretical value of 1.76 ( = nsapphire). The measured lateral resolution is as high as 0.64 μm. We show the practical utility of the sapphire immersion lens by imaging collagen-rich tissues with and without the solid immersion lens.
authors: Center for Nanometrology, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 304-340, South Korea.
authors: Eun Seong
authors: ES
authors: Lee
authors: Center for NanoSafety, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 304-340, South Korea.
authors: Sang-Won
authors: SW
authors: Lee
authors: Beckman Laser Institute, University of California, Irvine, California 92697, USA.
authors: Julie
authors: J
authors: Hsu
authors: Beckman Laser Institute, University of California, Irvine, California 92697, USA.
authors: Eric O
authors: EO
authors: Potma
keywords: (110.3080) Infrared imaging; (170.0180) Microscopy; (180.4315) Nonlinear microscopy; (190.4223) Nonlinear wave mixing