Alex Ren

Portable Digital Holography

For this project, a developed a portable version of a digital holography device in order to capture images that can be used to reconstruct 3D models of objects. I was tasked with developing this device for use in the Fluids Transport Lab at Johns Hopkins University. In testing, I was able to achieve a capture rate of 20,000 fps for a 10 mm field of view in ideal conditions. The device was built using COTS components and thus is easily replicable.

The device functions by filtering noise from a laser before recollimating the “cleaned” laser. A camera on the opposite side of the target object captures interference patterns between a reference wave and waves emanating from the target object. Numerical procedures are applied to the image to reconstruct the target object.

Through this project, I gained experience in working with optics. I learned about the precision required to successfully operate optical systems and further reinforced the importance of tolerances. For this device, slight misalignments in the optical lenses would result in unusable data.

Some changes I would make to this project are to use a more powerful laser to enable the device to function in a larger variety of situations and to use lens holders that are adjustable in millimeter increments. Without adjustability, it takes a lot of time to recalibrate the device.

I would like to thank Prof. Rui Ni for his support in this project.

Contact

aren40@gatech.edu
408-464-5891
Alex Ren | LinkedIn