Abstract
We have constructed an en face coherence gated camera for optically sectioning the in vivo human retina. Coherence gating is generated by a free-space Michelson interferometer employing a superluminescent diode for illuminating the retinal tissue; voice coil and piezo-electric translators for controlling the optical path length of the reference channel; and a scientific-grade CCD camera for recording 2-D retinal interferograms. A conventional 1-D OCT is incorporated for tracking the axial motion of the retina and controlling the gating position. En face slices of test objects and retinal tissue were obtained using a four-step (λ/4) phase shift method. Ultrafast acquisition of four interferograms in less than 7 milliseconds has been achieved to mitigate eye motion blur. A 5-step reconstruction algorithm that is more robust to phase shift error and noise was compared to the 4-step. The axial width of the point spread function and the sensitivity of the camera were measured near 10μm and 76 dB, respectively, which is substantially better than current flood-illuminated and confocal scanning laser ophthalmoscopes equipped with adaptive optics.
Original language | English (US) |
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Pages (from-to) | 352-359 |
Number of pages | 8 |
Journal | Proceedings of SPIE - The International Society for Optical Engineering |
Volume | 4956 |
DOIs | |
State | Published - Dec 5 2003 |
Externally published | Yes |
Event | PROGRESS IN BIOMEDICAL OPTICS AND IMAGING: Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine VII - San Jose, CA, United States Duration: Jan 27 2003 → Jan 29 2003 |
Keywords
- Adaptive optics
- Coherence gating
- Confocal scanning laser ophthalmoscope
- Eye
- Michelson interferometer
- Optical coherence tomography
- Retina
- Retina imaging
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Condensed Matter Physics