Line Field Optical Coherence Tomography

Abstract

The line field (LF) design choice for the lateral image formation mechanism (lateral format) has historically been a fraction of the whole optical coherence tomography (OCT) field. However, as the OCT technology develops, the parallelised acquisition of LF-OCT formats (LF-time domain (TD)-OCT, LF-spectral domain (SD)-OCT, LF-swept source (SS)-OCT) offers benefits and capabilities, which may mean it is now becoming more mainstream. Prior reviews on OCT have focused on scanning point (SP) and, to a lesser extent, full field (FF), lateral formats, with, to our knowledge, no prior review specifically on the LF lateral format. Here, we address this gap in the literature by reviewing the history of each LF-OCT format, identifying the applications it has had and providing generic system design overviews. We then provide an analysis and discussion of the benefits and drawbacks of the format.

Rapid imaging and product screening with low-cost line-field Fourier domain optical coherence tomography

“…By eliminating the need for its scanning unit (used for 3D imaging), such as the Galvo scanner and its controller, there is a possibility of reducing component expenses by approximately £2,000. This scan-free version can be particularly advantageous for in-line quality inspection on production lines, where harsh environments may pose a risk of damaging scanning mechanisms 57 .…”

Technology Selection for Inline Topography Measurement with Rover-Borne Laser Spectrometers

“…The ∆OPL is scanned spectrally, yielding superior sensitivity. A line-field setup may make use of the existing slit spectrometer, which provides the sensitivity gains of confocal detection [60]. However, scanning is needed in one lateral axis and sensitivity decreases with increasing object depth [61].…”

“…Spectrally swept sources based on VCSEL and fiber lasers have space heritage [64]. Coherent speckles, chromatic aberrations and pixel cross talk occur as areas of the image become defocused, restricting the measurable depth range [60]. SS-OCT will be worth further consideration when space-qualified MEMS-based tip/tilt 2D scanners become commercially available, allowing highly miniaturized, fiber-based OCT systems.…”