Measurement of the refractive index by using a rectangular cell with a fs-laser engraved diffraction grating inner...

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Accurate measurement of liquid refractive index is crucial for various scientific and industrial applications.
• Traditional methods for refractive index determination can be complex or require specialized equipment.

Purpose of the Study:

• To present a straightforward and accessible method for determining the refractive index of liquids.
• To utilize a custom-designed glass cell with an integrated diffraction grating for refractive index measurements.

Main Methods:

• A rectangular glass cell featuring a diffraction grating, fabricated via femtosecond (fs) laser ablation on an inner wall, was employed.
• A laser beam was directed normally onto the diffraction grating.
• The deviation of diffracted laser orders passing through the liquid-filled cell was measured.

Main Results:

• The deviation angles of the diffraction orders directly correlate with the refractive index of the liquid.
• This method provides a quantifiable relationship between laser beam deviation and liquid refractive index.

Conclusions:

• The developed method offers a simple and effective approach to measure liquid refractive indices.
• The use of a fs laser-ablated diffraction grating within a glass cell simplifies the experimental setup and measurement process.