Therefore it is desirable to be able to change the lenses that are in the optical path to provide specialty optics when desired.
The reticle collimation optics are situated at 90° to the optical path making lighting difficult, usually needing additional electric illumination, condensing lenses, etc.
In addition to the obvious size advantage of integrated optics, other benefits include reproducibility and mass production capability, and long-term optical path and phase stability.
Schlieren optics show changes in the condition of a test area of space in the optical path, even when it remains fully transparent.
The optics for providing a telephoto lens and other specialty lenses require a certain length for their optical path, which often is unavailable within a small device.
9, 10 Theoretical limits for the possible optical path enhancement of bulk architectures have long been established to be 4 n for unpolarized light in the ray optics approximation.
The scanning optics (Fig. 3) consisted of a collimator, a microscope objective (5x Plan Apo NIR Infinity-Corrected Objective, Mitutoyo, Japan), two galvanometers for x-y scanning (Thorlabs, Newton, NJ), and five mirrors for folding the optical path.
Zemax (Zemax Development, Bellevue, WA) and ASAP Breault Researchh, Tucson, AZ) optical modeling software were used to characterize beam propagation of the OCT and LIF optical paths through the distal optics.
Too much sunlight bounces around inside the optics, following paths that the lens-makers did not intend, and leaving behind extraneous circles of light on the sensor or film.
Commercial optical coherence tomography (OCT) systems are capable of switching between anterior and posterior imaging modes; however, switching modes requires the addition or removal of optics from the sample path and adjustment of the reference path.
Under the computer controlling, the "small tool" polishes the optics with the planned path, and the dwell time of each dwell point along the path which is determined by the surface error.
