01
Singlets
Plano- and biconvex, Ø 3 – 150 mm, N-BK7 or fused silica.
from€ 38
Light, bent to λ/20.
Focal lengthf′ 100.8
Spot Ø · mm38.9
Colour · mm11.1
Caustica grinds, polishes and interferometrically tests custom optics — single lenses to complete objectives — for labs that measure their mistakes in nanometres.
02 / 05 Achromat
Two glasses.
One focus.
A single lens brings blue to focus before red, so every bright point wears a rainbow. We cement a crown element to a flint one and let their errors cancel — keep scrolling and watch the fringes at the focus collapse into one white point.
Longitudinal colour
11.1mm
Singlet N-BK7Crown + flint, cemented
03 / 05 — Dispersion
White in. Spectrum out.
Prisms polished to λ/20 on every face
The glass decides where each colour lands.
Turn the prism and the spectrum sweeps across the target. That is the whole trade: knowing, to the arcsecond, where the light will go.
Materials 01
Fused silica, N-BK7, calcium fluoride, sapphire and zinc selenide — from the deep UV at 193 nm to the thermal infrared at 12 µm.
Surfaces 02
Faces flat to λ/20 and angles held to ±2 arcseconds, checked on a Fizeau interferometer before anything is coated. Every part ships with its interferogram.
Coatings 03
Broadband anti-reflection under 0.25 % per surface, or dichroic edges placed to the nanometre you specify, in our own ion-assisted chamber.
04 / 05 Catalogue
Stock parts ship in 48 hours.
Couple the beam into the bundle and ten thousand cores carry it to the target. The same glass, cut and polished, is on the shelf.
02
Achromats
Cemented crown–flint doublets for VIS and NIR, centred to 0.4″.
from€ 120
03
Prisms
Equilateral, right-angle, Pellin–Broca and Amici, faces to λ/20.
from€ 95
04
Fibre bundles
Coherent imaging bundles, 10 000 cores, 1.2 m, polished SMA ends.
from€ 640
05
Windows & flats
Reference flats to Ø 200 mm at λ/20, windows wedged or parallel.
from€ 210
06
Your drawing
Send an ISO 10110 drawing; we return a price and the interferogram we will hold ourselves to.
quoted in3 days
05 / 05 — Assembly
Everything above, in one barrel.
Eleven elements · eight groups · one focus
CX-50 Apochromatic objective
Built one surface at a time.
Our own 50 mm f/1.4 for machine vision and microscopy relay. Drag the focus and watch the spot open into a disc and snap back to a point.
0Elements · 8 groups
f/0Maximum aperture
0MTF at 100 lp/mm
λ/0Every surface
Quote Three working days
Send us a drawing.
Every enquiry gets a price, a lead time and the wavefront figure we will sign for. If we can't measure it, we won't sell it.