Full-field interferometric confocal microscopy using a VCSEL array.

Area of Science:

• Optical microscopy
• Biomedical imaging
• Laser technology

Background:

• Confocal microscopy offers high-resolution optical sectioning but typically requires scanning mechanisms.
• Existing methods often lack speed or the ability to capture phase information.
• Advancements in laser technology and interferometry can potentially overcome these limitations.

Purpose of the Study:

• To develop a novel interferometric confocal microscope.
• To achieve high-speed, snapshot en face plane imaging.
• To enable quantitative phase measurements alongside intensity imaging.

Main Methods:

• Utilizing an array of 1200 vertical cavity surface emitting lasers (VCSELs) coupled to a multimode fiber.
• Implementing spatial coherence gating to create ~18,000 virtual pinholes.
• Employing interferometric detection for phase recovery.

Main Results:

• The system achieves confocal optical sectioning without mechanical scanning.
• Snapshot imaging of an entire en face plane is demonstrated.
• High-speed acquisition with integration times as short as 100 μs is possible due to high VCSEL power (~5 mW per laser).
• Quantitative phase measurements and improved contrast for phase objects are achieved.

Conclusions:

• The developed interferometric confocal microscope provides a powerful, fast, and versatile imaging solution.
• This technology offers advantages over traditional scanning confocal microscopes, particularly for dynamic or large-area imaging.
• The ability to capture both intensity and phase information enhances its utility in various scientific fields.