Optical Lenses & Filters

Optical Lenses & Filters — Fused Silica · Sapphire · Ge · ZnSe

Name: Optical Lenses & Filters
Brand: DOWA Electronics
Availability: InStock

Sourced across China, Taiwan, Germany — we supply Fused Silica, Sapphire, CaF₂, MgF₂, Ge, ZnSe optics covering UV through IR.

MATERIALS

Materials

Fused Silica

UV – VIS – NIR

Sapphire

UV – IR

CaF₂

Deep UV – MWIR

MgF₂

Deep UV – MWIR

MWIR – LWIR

ZnSe

VIS – LWIR

BK7

VIS – NIR

Silicon

MWIR

TYPES

Product types

Plane optics — windows, plates, filters

Prisms — right-angle, polarising cube beamsplitters

Spherical/aspheric lenses — collimating, focusing, telecentric, CCTV

Filters — IR bandpass, polarising, custom coatings

PRECISION

Precision specifications

Supporting high-precision specs such as PV λ/20 and Surface Quality 10-5. COC, measurement data, and custom engineering provided on consultation.

PV λ/20SD 10-5COCAR CoatingCustom Filter

MATERIAL COMPARISON

Material comparison

Choosing the right material for your wavelength band is the starting point of optical design. Key materials with their transmission range, traits, and typical uses.

Material	Transmission	Traits	Typical use
Fused Silica	180 nm – 2.1 μm	Low CTE · high laser-damage threshold	UV optics · high-power laser · spectroscopy
Sapphire	150 nm – 5.5 μm	Ultra-hard · scratch/chemical resistant	Protective windows · harsh environments
CaF₂	130 nm – 10 μm	Broadband · low dispersion	Deep UV · FTIR · MWIR spectroscopy
MgF₂	120 nm – 7 μm	VUV transmission · birefringent	VUV windows · AR coatings
Ge	2 – 14 μm	High index · opaque to visible	Thermal imaging · LWIR lenses
ZnSe	0.6 – 16 μm	Low absorption · CO₂ laser standard	CO₂ laser optics · thermal imaging
Silicon	1.2 – 8 μm	Lightweight · low-cost IR	MWIR lenses · filter substrates
BK7	350 nm – 2 μm	General-purpose visible glass	Visible lenses · windows

RECOMMENDATION

Recommended material by application

UV sterilisation / curing optics

For 200–400nm deep UV, Fused Silica and CaF₂ are standard. Ordinary BK7/soda-lime glass absorbs UV and is unsuitable. Fused Silica offers excellent transmission at 248/308/365nm and high thermal/chemical stability — ideal for UVC sterilisation module windows.

IR · SWIR sensing / machine vision

1–3μm SWIR suits Sapphire/Fused Silica; 3–5μm MWIR suits Sapphire (~5μm)/CaF₂; 8–12μm LWIR suits Ge/ZnSe. Ge has high 8–12μm transmission but is opaque to visible; ZnSe spans visible–LWIR and is widely used in CO₂ laser optics.

High-power / CO₂ lasers

ZnSe has very high 10.6μm CO₂ laser transmission with low absorption loss — the standard for focusing lenses and windows. In high-energy setups, Fused Silica (355/532/1064nm) is preferred for its high laser-damage threshold.

WHY DONGHWA IND

Why DONGHWA IND

Full-spectrum single supply

From UV (Fused Silica/CaF₂) to LWIR (Ge/ZnSe) in one place. Bundle LEDs, filters, and lenses without juggling multiple vendors.

Multi-sourcing — price & lead time

Leveraging China/Taiwan/Germany hubs to optimise for spec, budget, and delivery. Removes the customs, FX, and communication risk of direct overseas import.