Selectable-wavelength low-coherence digital holography with chromatic phase shifter

Area of Science:

• Optics and Photonics
• Digital Holography
• Spectroscopy

Background:

• Digital holography typically uses monochromatic light sources.
• Measuring spectral properties of objects in holography is challenging.
• Existing methods have limitations in dynamic range and flexibility.

Purpose of the Study:

• To develop a new digital holography method for spectral property measurement.
• To enable flexible single- and multi-wavelength holographic imaging.
• To achieve a wide dynamic range in holographic measurements.

Main Methods:

• Utilizing an ultra-broadband light source.
• Employing a chromatic phase-shifter for frequency-dependent phase shifts.
• Analyzing spectral data in the temporal frequency domain.
• Conducting theoretical analysis, computer simulations, and optical experiments.

Main Results:

• The proposed method successfully measures the spectral properties of objects.
• Demonstrated capability for arbitrary selection of signals in the temporal frequency domain.
• Achieved single- and multi-wavelength measurements with a wide dynamic range.
• Validated through theoretical analysis, simulations, and experiments.

Conclusions:

• The novel digital holography method offers significant advantages for spectral analysis.
• The chromatic phase-shifter is key to enabling flexible spectral measurements.
• This technique enhances the capabilities of digital holography for material characterization.