asphericon periodically reports on our Blog about exiting and current issues in the field of optics/photonics. Rate and comment on entries or address new topics for future entries by using our contact form. We look forward to your feedback!

Topic: Coating, Optics

Optical coating methods: Thin films for optical systems

Modern optical coating technologies After introducing the field of optical coating, e. g. via filter and anti-reflective coatings, beam splitter and dielectric mirrors, the following article shows how to obtain the coating materials with the desired properties on optics made of glass, metal or other materials. Optical coatings are used in a variety of applications, […] Read more

Topic: Optics

High-performance optical coating for demanding applications

Precision optical components such as lenses or mirrors are almost always provided with an optical coating. The applied layers have different effects, such as the enhancement of transmission of certain wavelengths or the reduction of reflection. However, an optical coating is not only used in optics and technology sectors, but also in everyday objects such […] Read more

Topic: Optics

Cleaning optics properly

A guide to handling and cleaning optics The basic requirement for a long lifespan and the preservation of quality of precision optics is the high level of care in handling and cleaning. Depending on the material, the coating as well as the degree and type of contamination, various things must be considered. In the following, […] Read more

Topic: Asphere

Aspheric Myths Part 2

Precision and production myths Aspheric production has undergone an enormous development in the areas of manufacturing and metrology. Nevertheless, there are many rumors about this special type of lens, for example that aspheres are very expensive and can only be measured with CGHs. Some of these myths have already been addressed in the previous article […] Read more

Topic: Asphere, Optics

Aspheric myths – facts and fiction

Part 1: Geometry, metrology and quality myths Aspheres are becoming increasingly important and have become standard components in many areas of application. They can be found in photo lenses with high luminous intensity or wide-angle lenses, in endoscopes, magnescope and telescopes, but also in high-tech applications such as aerospace. With the development of modern manufacturing […] Read more

Topic: Asphere, Beam Shaping

Shape it ‘til you make it – Top-Hat beam shaping with aspheres

Gaussian beam profiles are used in most laser applications. However, there are fields of application in which a homogeneous intensity distribution (so-called Top-Hat distribution) is required within the entire beam diameter, for example in order to generate optimum illumination. Especially in the fields of metrology, microscopy or material processing, homogeneous intensity distributions play a significant […] Read more

Topic: Measurement

Noncircular in perfection – Interferometric Measurement of Aspheres

Optische Messtechnik, Interferometer, Measurement, transmission sphere, Fizeau, Objektiv, lens, objective
Production-accompanying measurement of aspheres – Part 2: How does a Fizeau interferometer work? The first article of this series addressed the detailed description of tactile measuring procedure. The following contribution focuses on the non-contact measurement of aspheres with the help of interferometers, in order to describe optical measuring methods. Interferometers are standard instrument for measuring […] Read more

Topic: Measurement

Noncircular in perfection – Comparison of tactile measurement methods

Production accompanying measurement of aspheres – Part 1: Tactile measurement methods Independent of the application, whether in satellite optics, video lenses or endoscopes – aspheres have already become indispensable in a wide range of highly versatile technical fields of application. Regardless of the system’s size, they all have to meet one requirement: to be precise. […] Read more

Topic: Optics

Improving focusing quality of spherical lenses

Header_Improving focusing quality
Introduction The generation of Bessel beams with axicons is the most noted application for this uncommon type of aspherical surfaces. A more complex setup (Fig 1.) of combining several axicons and a common spherical lens will be the main aspect in the beam shaping consideration within this article. It will be demonstrated how the focusing […] Read more

Topic: Beam Shaping, Optics

Various beam shaper applications utilizing axicons

Axicons are conical lenses which create a ring-shaped beam used in research or rather different laser applications. They can be either convex or concave and made from almost any optical material. By combining two or more axicons and lenses multiple intensity profiles can be created. Specifics and Bessel beam creation Axicons are commonly used to […] Read more

Topic: Beam Expansion

Beam Expansion

Beam expansion is a method to expand or reduce a light or laser beam, that is realized by an optical system (beam expansion system). Read more

Topic: Optics

Freeform Optics Plus (fo+)

Since 2014, asphericon has been working with its partners on the Freeform Optics Plus (fo+) research project. Read more

Topic: Optics

Aspheric optic for DHM

asphericon_digital holographic microscopy
Recent advances in digital technologies have led to an increasing interest in the science and engineering of digital holographic microscopy (DHM). Read more