In General:

• Howstuffworks.com tells you how stuff works! It's that easy and helpful!

Online Tools:

• Matrix Calculator

About CRDS:

• Cavity Ringdown Spectroscopy with CW Lasers.
• Interesting animation demostration.
• CRDS research with setup pictures.
• Background and motivation of CRDS.
• APS abstracts, April 1997

About Wavelength Measuring:

• Messy math equations.

About Barium Titanate:

• its behavior.
• various types of crystals.
• experiment on BCT(BTO with calcium).
• abstracts.
• Summary of Photorefractive crystals.
• thesis.
• photorefractives.