Optics explained

All types of optical components explained

By 1 October 2020 No Comments
custom optical components

Lenses are available in many shapes, sizes and materials. They can be made from a single piece of glass, or have multiple elements. Lens surfaces can be spherical, aspheric or cylindrical. They can be created from common glass materials or from more complex materials. Let’s take a closer look at optical elements that are used for light manipulation.

What are optical components?

Optical components fall into two groups: transmissive optical components and reflective optical components.

Transmissive optical components

This group contains lenses, filters, windows, optical flats, prisms, polarizers, beam splitters, wave plates and fiber optics.

Reflective optical components

This group contains mirrors and reflectors. Performance of reflectives can be enhanced by using certain substrates or optical coatings.

Optical components overview

Let’s take a closer look at each of the individual components.

Lenses

There are many types of lenses available: plano convex, biconvex, plano concave, biconcave, meniscus (concave/convex) and aspheric. The lens shape that is best suited for a particular optical system (because it minimizes spherical aberration) is called best-form. For imaging applications at unit magnification (object distance equals image distance) a symmetric biconvex lens is best-form, as it will also reduce distortion and lateral chromatic aberration as they cancel each other out. This is true regardless of wavelength or material index and explains the utility of symmetric convex lenses, as well as symmetrical optical systems.

Types of lenses

  • Spherical lenses
  • Aspherical lenses
  • Achromatic lenses
  • Cylindrical lenses
  • Powell lenses
  • GRIN lenses

Addoptics makes lenses in all shapes and sizes. Are you curious if we can manufacture your optical design? Feel free to reach out to us.

Mirrors

Mirrors can be used to image, redirect and focus light. Mirrors come in many shapes, sizes and configurations. They can be made from glass, metal or plastic. Mirrors are mostly flat (plane), spherical or pyramidal. Last but not least, they can be coated or uncoated. At Addoptics we can create polymer based metal mirrors by using an aluminum coating.

A mirror’s reflective properties are based on the wavelength, angle of incidence and polarization of the incident light.

Metal mirrors are most often not coated, as they can rely on the highly polished surface to reflect light. Mirrors made from other materials can be coated with a metallic or dielectric coating.

Plane mirrors are used to redirect light along an optical path or to fold optical systems. With minimum effort they can transfer radiation on wavefront or image quality. Plane mirrors can also be combined to change the orientation of an image.

Types of mirrors

  • Broadband dielectric mirrors
  • Laser line mirrors
  • Ultrafast mirrors
  • Plano metallic mirrors
  • Dichroic mirrors / beam splitters

Addoptics is able to create mirrors by having plastic optical components coated with an aluminum coating.

Filters

Filters enhance or alter the characteristics of a beam of light either by changing the intensity of the beam (without affecting it spectral content) or by changing or separating the spectral content of the beam (through wavelength-selective absorption or reflection).

Neutral density filters will change the overall intensity of the beam without affecting its spectral content. Filters that will change the spectral content of the beam through wavelength-selective absorption or reflection are high-pass, low-pass, edge, dichroic and interference filters.

A commonly used filter material is thin metallic film. The reflective properties of metallic films, like Inconel, chromium and nickel, are relatively insensitive to wavelength.

Optical densities of neutral density filters used in combination are additive if multiple reflections between filters do not occur in the direction of interest. Filter combinations allow for values of transmittance or density that would otherwise not be available.

Interference filters are multilayer thin-film components that identify and isolate specific regions by reflecting longer wavelengths and absorbing the shorter ones. These filters provide a simple, cost-effective way to isolate a specific wavelength or even wavelength range.

Beams are split, combined or attenuated by neutral density filters, with basically no dependence on wavelength. The amount of transmission is based on the thickness of the coating.

If you are looking for polymer-based filters, feel free to contact us so we can discuss the possibilities.

Types of filters

  • Polymer optical filters
  • Spectral filters
  • Colored glass filters
  • Neutral density filters
  • Spatial filters

Prisms

A prism is a block of optical material with polished, flat sides arranged at controlled angles. Angle specification is critical, as even small errors can inhibit proper operation. Prisms are used to invert or deviate light, or rotate an image, disperse light into component wavelengths and to separate polarization states. Many prisms make use of the total internal reflection property.

Light incident upon air/optic boundary at angles greater than the critical angle is totally reflected.

Some applications of prims include: bend light through 90° (right-angle prims). The dove prism is used as an image rotator. The roof prism deflects light by 90° and also inverts the image. The wedge prism can be used for beam steering.

Types of prisms

  • Right-angle prisms
  • Roof prisms
  • Retroreflector prisms
  • Unmounted dove prisms / unmounted penta prisms
  • Mounted dove prisms / mounted penta prisms
  • Wedge prisms
  • Coupling prisms

Diffusers

Diffusers scatter incident light evenly. The amount and distribution of light is based on surface quality, rough surfaces scatter more light. Diffusers can reduce the intensity present in a beam by scattering the light in several directions.

Types of diffusers

  • Holographic diffusers
  • Ground glass diffusers

Custom optical components

Are you looking for custom optical components? Feel free to reach out to us to discuss your project requirements. We can help manufacture custom lighting optics, for instance. Or help you with optical prototypes.

If you require one of the above mentioned optical components feel free to contact us and e-mail your optics design. Together we can discuss design feasibility based on the capabilities of our unique optics manufacturing method.

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