Simple, portable, and low-cost microscope based on off-axis digital holography using two spherical waves.

Area of Science:

• Optics and Photonics
• Biomedical Imaging
• Microscopy

Background:

• Holographic microscopy offers advanced imaging capabilities.
• Existing systems can be complex and expensive, limiting accessibility.

Purpose of the Study:

• To develop a highly compact and low-cost holographic microscope.
• To enable real-time imaging of transparent samples, including those in microchannels.

Main Methods:

• Utilized an inexpensive laser diode, a dual precision round aperture, and a digital light sensor.
• Captured off-axis interference patterns of spherical waves.
• Reconstructed quantitative phase and amplitude images with real-time twin-image elimination.

Main Results:

• Achieved a system cost under $400 (excluding sensor).
• Demonstrated a resolution better than 2 micrometers.
• Successfully retrieved the 3D structure of blood cells.

Conclusions:

• The developed holographic microscope is cost-effective, compact, and suitable for various transparent samples.
• The system's capabilities support potential applications in portable, real-time biological imaging.