Optical Low-pass Filter Birefringent Material "Lithium Niobate"｜光学产品｜Product Lineup｜产品信息｜NDK

Lithium niobate (LiNbO₃) single crystal is used as the birefringent material [Photo 1].
With a thickness of about 1/6 that of a quartz birefringence plate, the same ray separation width can be obtained [Photo 2].

[Photo 2: Comparison of Thickness Between Quartz Crystal and Niobate]
Left: Four Pieces of Quartz Crystals Bonded Together
Right: Four Pieces of Lithium Niobate Bonded Together

Standard Specifications

Birefringence Plate Refractive Index	Ordinary rays no=2.3198、Abnormal rays ne=2.2308
Ray Separation Width	Available in the range of 4.4μm or more.
External Dimensions	Available in the range of 10~60mm × 10~60mm.
External Dimensional Tolerance	Available in the range of ±0.1mm or more.
Thickness Per a Substrate	Available in the range of 0.135mm or more.
Thickness Dimension Tolerance	Available in the range of ±0.01mm or more.
AR Coat Reflectance	1.0% Max.(420~700nm) When using BK7 etc. as a cover glass, 0.5% Max.(420~700nm) is guaranteed.
Bonding	If multi-pointseparation is required, two or substrates can be bonded together.

External Dimensions
Supported Within the Dimensions Shown on the Right

We will consider requests for other external dimensions, so please feel free to contact us.

*Please inquire for special specifications.

Optical Characteristics Example

LiNbO₃ Base Plate

OLPF

Warranty Items

Test items include temperature, humidity, impact resistance, heat resistance, etc. for the environmental and mechanical properties of optical components.
We set test items and conditions for each component and guarantee the properties of the component. However, warranty items and conditions vary depending on the shape, properties, application, and environment of the optical component.

Subjected to High Temperature	85℃　1000H
Subjected to Low Temperature	-40℃　1000H
Subjected to High Temperature and High Humidity	60℃90％RH～95%RH　1000H
Heat Shock	-40℃　2H 、85℃　2H、100℃/H　10 Cycles
Subjected to Thermal Shock	-40℃/85℃　30 Minutes Each　100 Cycles
Coating Adhesion Strength	Cellophane tape (LP-18) is applied to the component, rubbed with the fingers three times, and then quickly pulled off in a vertical direction ten times
Abrasion Resistance	The vapor-deposited surface is pressed with lens-cleaning paper (DUSPER K-3) with a pressing pressure of 4.9 N/cm² (500 gf/cm²) 1 round-trip/second continuous, round-trip distance 10 mm, 100 round-trips
Solvent Resistance Test	Using lens-cleaning paper (DUSPEP K-3) in solvents such as IPA, acetone, ethanol, etc. with 2.94 N (300 gf) 1 round-trip/second continuous, round-trip distance 100 mm, 100 round-trips