High-depth-resolution range imaging with multiple-wavelength superheterodyne interferometry using 1550-nm lasers

Area of Science:

• Optics and Photonics
• Metrology
• Machine Vision

Background:

• Lasers are crucial for optical imaging, with Time-of-Flight (ToF) cameras offering meter-range but centimeter-resolution, and interferometry providing micrometer-resolution but sub-millimeter range.
• Existing laser-based range imaging techniques present a trade-off between imaging range and depth resolution.

Purpose of the Study:

• To develop a range imaging system that overcomes the limitations of current technologies.
• To achieve simultaneous sub-millimeter depth resolution and an imaging range of tens to hundreds of millimeters.

Main Methods:

• Implementation of a multi-wavelength superheterodyne interferometry system.
• Utilization of two tunable III-V semiconductor lasers.
• Design of a fiber-connected system with a scanning head for portability.

Main Results:

• The proposed system enables simultaneous sub-millimeter depth resolution and an extended imaging range.
• The system's design allows for adjustable trade-offs between imaging range and resolution.
• The fiber-optic construction facilitates the development of a portable device.

Conclusions:

• The novel multi-wavelength superheterodyne interferometry system offers a significant advancement in range imaging.
• This technology has the potential to greatly benefit fields like metrology and computer vision.
• The system provides a unique combination of high resolution and practical imaging range.