Range selective phase-shifting frequency-modulated digital holography with temporal-heterodyning

Area of Science:

• Optics and Photonics
• Digital Imaging
• Holography

Background:

• Traditional digital holography often struggles with range selectivity and background noise.
• Frequency-modulated continuous wave (FMCW) techniques offer potential for improved depth resolution.
• Time of flight (TOF) cameras provide depth information but integrating them with holographic methods is challenging.

Purpose of the Study:

• To demonstrate range selective temporal-heterodyne frequency-modulated continuous wave digital holography (TH FMCW DH) using a TOF camera.
• To achieve high range resolution and efficient hologram integration at a selected depth.
• To enable on-axis holographic geometries for improved signal-to-noise ratio.

Main Methods:

• Utilizing a TOF camera for modulated arrayed detection.
• Implementing temporal-heterodyne detection for FMCW digital holography.
• Employing on-axis holographic geometries to filter out unwanted background light.
• Achieving range selectivity by integrating holograms at a specific depth.

Main Results:

• Successful demonstration of range selective TH FMCW DH imaging.
• Obtained range resolutions significantly less than the optical system's depth of field.
• Achieved on-axis DH geometries with effective background light filtering.
• A 2.39 GHz FMCW chirp bandwidth yielded a DH range resolution of 6.3 cm.

Conclusions:

• TOF cameras are suitable for range selective TH FMCW DH.
• The developed method offers superior range resolution and background suppression.
• This technique opens possibilities for advanced 3D imaging applications.