Acousto-optic tunable filter as a polychromator and its application in multidimensional fluorescence spectrometry

Area of Science:

• Optics and Photonics
• Spectroscopy
• Analytical Chemistry

Background:

• Acousto-optic tunable filters (AOTFs) are electronically controlled dispersive devices utilizing acousto-optic interaction.
• AOTFs diffract specific wavelengths of incident light when subjected to radio frequencies (RF).
• Conventional polychromators lack individual wavelength amplitude modulation capabilities.

Purpose of the Study:

• To develop an AOTF-based polychromator with individual amplitude modulation for each diffracted wavelength.
• To introduce a novel multidimensional fluorimeter utilizing AOTF technology.
• To demonstrate the analysis of multicomponent samples using the developed AOTF fluorimeter.

Main Methods:

• Utilizing an acousto-optic tunable filter (AOTF) for light diffraction and wavelength selection.
• Simultaneously exciting samples with two wavelengths (514.5 and 488.0 nm) modulated at distinct frequencies (100 and 66 Hz).
• Applying sinusoidal modulation to individual RF signals applied to the AOTF for amplitude control.

Main Results:

• Demonstrated the ability to individually amplitude-modulate multiple wavelengths diffracted by the AOTF.
• Successfully developed and implemented a novel AOTF-based multidimensional fluorimeter.
• Analyzed multicomponent samples, such as mixtures of rhodamine 6G and rhodamine B, with high accuracy.

Conclusions:

• The AOTF polychromator offers significant advantages over conventional methods due to its electronic control and modulation capabilities.
• The developed AOTF-based multidimensional fluorimeter is effective for analyzing complex mixtures.
• This technology provides a new platform for advanced spectroscopic analysis and sample characterization.