Bayesian uncertainty evaluation applied to the tilted-wave interferometer.

The tilted-wave interferometer is a promising technique for the development of a reference measurement system for the highly accurate form measurement of aspheres and freeform surfaces. The technique combines interferometric measurements, acquired with a special setup, and sophisticated mathematical evaluation procedures. To determine the form of the surface under test, a computational model is required that closely mimics the measurement process of the physical measurement instruments.

Evaluation of absolute form measurements using a tilted-wave interferometer.

Tilted-wave interferometry is a promising measurement technique for the highly accurate measurement of aspheres and freeform surfaces. However, the interferometric fringe evaluation of the sub-apertures causes unknown patch offsets, which currently prevent this measurement technique from providing absolute measurements. Simple strategies, such as constructing differences of optical path length differences (OPDs) or ignoring the piston parameter, can diminish the accuracy resulting from the absolute form measurement.

Analytical Jacobian and its application to tilted-wave interferometry.

Tilted-wave interferometry (TWI) is a novel optical measurement principle for the measurement of aspherical surfaces. For the reconstruction of the wavefront and the surface under test, respectively, perturbation methods are applied, which require the calculation of the Jacobian matrix. For the practical use of the instrument, a fast and exact calculation of the Jacobian matrices is crucial, since this strongly influences the calculation times of the TWI.

Assessment of tumor thickness in melanocytic skin lesions: comparison of optical coherence tomography, 20-MHz ultrasound and histopathology.

Background: Accurate assessment of vertical tumor size is important for surgical treatment planning of melanocytic skin lesions. High-frequency ultrasound (HFUS) is frequently used for this purpose, but overestimation of tumor thickness is known as a problem especially in thin melanocytic lesions. Optical coherence tomography (OCT) as a new imaging technique might be a promising alternative.

Preoperative characterization of basal cell carcinoma comparing tumour thickness measurement by optical coherence tomography, 20-MHz ultrasound and histopathology.

Optical coherence tomography (OCT) is a new imaging method with promising results for several dermatological indications, including preoperative skin tumour characterization. While high-frequency ultrasound (HFUS) is frequently used for this purpose, overestimation of tumour thickness is a problem, due to subtumoral inflammatory infiltration that cannot be differentiated from tumour tissue. The aim of this single-centre study was to describe OCT features of basal cell carcinoma (BCC) and to determine vertical tumour thickness accurately, including a comparison with HFUS and histopathology.