Imaging Collagen Orientation Using Polarization-Modulated Second Harmonic Generation
We use polarization-modulated second harmonic generation to image fiber orientation in collagen tissues, with an axial resolution of about 10 {micro}m and a transverse resolution of up to 1 {micro}m. A linearly polarized ultra-short pulse (200 fs) Ti:Sapphire laser beam is modulated using an electro-optic modulator and quarter-wave plate combination and focused onto a translation stage mounted sample using a microscope objective. The generated second harmonic light is collected using a photomultiplier tube and demodulated using phase sensitive detection to obtain signal intensity and fiber orientation information. In order to obtain second harmonic generation images of different types of collagen organization, we analyze several different tissues, including rat-tail tendon, mouse aorta, mouse fibrotic liver, and porcine skin. We can use our technique to image fibrotic tissue in histological sections of damaged liver and to identify burned tissue in porcine skin to a depth of a few hundred microns. Polarization-modulated second harmonic generation potentially could be a useful clinical technique for diagnosing collagen related disease or damage, especially in the skin.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 15013321
- Report Number(s):
- UCRL-JC-147008; TRN: US200802%%1147
- Resource Relation:
- Conference: SPIE for the Biomedical Optics Section of Photonics West 2002, San Jose, CA, Jan 19 - Jan 25, 2002
- Country of Publication:
- United States
- Language:
- English
Similar Records
Measurement of the Second Order Non-linear Susceptibility of Collagen using Polarization Modulation and Phase-sensitive Detection
Coherent X-ray diffraction from collagenous soft tissues