Although YPT does not have the in-house capability to manufacture glass optical components, we work closely with well established Yorkshire based lens manufacturer, RDT Precision Optics. Below is a brief description of RDT's products, but for further information click here to go to RDT's web site....   

RDT Precision Optics

RDT has comprehensive facilities for the manufacture of : Lenses Flats & Windows Filters Mirrors Graticule Blanks

Lenses (Page Top)

• Bi Convex Lenses
• Bi Concave Lenses
• Plano Convex
• Plano Concave
• Meniscus
• Achromatic Doublet Lenses

Sizes range from 2.50mm diameter to 150mm diameter. Lenses can be manufactured from most optical glasses including fused silica and filter glass.

Tolerances typically :-

• +0/-0.1mm diameter
• +/-0.05mm centre thickness
• +/-3 fringes power
• 1/5 fringe form error
• 3 minutes of arc Centration

Fire polished aspheric lenses. Aspheric faces are moulded or fire polished. Opposite faces are optically polished using conventional pitch polishing methods or high speed diamond smoothing and polishing to achieve good optical performance and improved cosmetics.

Flats & Windows (Page Top)

Optical windows in a wide range of optical glass and filter glass, including fused silica, with diameters from 2.5mm to 150mm and thicknesses down to 0.5mm.

Tolerances are typically:-

• +/- 0.05mm diameter
• +/- 0.025mm thickness
• 1/5 fringe flatness
• 30 seconds parallel

As well as plano/plano windows we can also offer spherical domed windows. Optical diffusers are usually manufactured from heat resistant glass, but are also available in optical glass, filter glass and fused silica. Typically one face is optically polished and the opposite face is flashed with a specific abrasive to give the required diffusion. Sizes range from 2.5mm to 150mm diameter and square or rectangular diffusers can be supplied.

Filters (Page Top)

Absorption filters can be offered, usually in Schott™ filter glass. Alternative equivalent filter glass types from America or the Far East can also be offered, often at considerable cost savings.

By using our spectrophotometer, we can precisely measure the spectral performance of a filter from 200nm to 1100nm, ensuring the correct and reproducible performance when using equivalent filter glass types. Spectrophotometry also gives RDT the capability to precision lap and polish neutral density filters to give the correct optical density in a reproducible fashion. All dielectric thin film filters can also be offered through YPT.

Sizes from 2.5mm to 150mm in diameter and 5mm to 150mm square with tolerances of ± 0.1mm can be offered.

Mirrors (Page Top)

Plano and spherical mirrors in sizes similar to lenses and flats, with similar tolerances. Mirrors can be made from a range of materials, including those which are thermally stable.

Reflective coatings can be deposited at YPT using a range of materials. Protected and enhanced metal coatings, including second surface designs, can be deposited with excellent adhesion to US MIL-M-13508C. For very high reflectances over a limited bandwidth, all dielectric coatings can be offered.

A wide range of square, round and concave mirrors with protected aluminium coatings are carried in stock. Contact RDT directly for details.

Graticule Blanks (Page Top)

RDT Optics Ltd has access to photolithography for graticule definition and has extensive experience of supplying graticule blanks either uncoated or coated with pinhole free chromium to an optical density of five. By using our well conditioned twin lap polishing machines we can achieve extremely tight cosmetic specifications on a range of materials.

Similar technology is also used to manufacture lighting gobos and gobo blanks. Gobo blanks can be offered in heat resistant materials, including fused silica.