Calcium Fluoride Optical Member Crystal Orientation

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Solution Overview

Problem

Monocrystalline calcium fluoride optical members lack sufficient strength in high-temperature and high-pressure environments, making them unsuitable for certain applications.

Innovation Solution

A manufacturing method for a calcium fluoride optical member involves machining monocrystalline calcium fluoride into a tubular shape with the {110} or {111} crystal plane orthogonal to the center axis, optimizing the crystal plane arrangement to enhance strength under pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If monocrystalline calcium fluoride is used as an optical member, then high transmittance across wide wavelength range is achieved, but insufficient strength in high-temperature and high-pressure environments occurs

Engineering Contradiction:
Improvelight transmittanceVSAvoidstrength in high-temperature and high-pressure environments
Core Design Contradiction:
Illumination intensityVSStrength

Solution Approach 1:

The patent applies parameter changes by optimizing the crystal plane orientation parameter. Specifically, it identifies that machining the monocrystalline calcium fluoride so that the <110> or <111> crystal plane is orthogonal to the tube center axis creates optimal mechanical strength. This parameter optimization resolves the contradiction by maintaining the inherent high transmittance property while achieving sufficient strength through crystallographic orientation control.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If conventional machining of monocrystalline calcium fluoride is performed without crystal plane consideration, then manufacturing simplicity is maintained, but insufficient strength in demanding environments results

Engineering Contradiction:
Improvemachining simplicityVSAvoidreliability in high-temperature and high-pressure environments
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary action by identifying and orienting the crystal planes <110> or <111> to be orthogonal to the tube center axis before final machining operations. This preliminary crystallographic orientation ensures that subsequent machining processes produce components with optimized mechanical properties, thereby achieving both manufacturing feasibility and high reliability in demanding environments.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3113210B1Calcium fluoride optical member, manufacturing method therefor, gas-holding container, and light source device
Publication Date: 2018.11.07 NIKON CORP
  • EP3113210B1 patent drawingFigure 1
  • EP3113210B1 patent drawingFigure 2
  • EP3113210B1 patent drawingFigure 3A~3C

AI summary

Provided is a CaF2 monocrystalline optical member reliably usable even at a high temperature and under a high pressure. A calcium fluoride optical member (1) is formed of monocrystalline calcium fluoride and has a tubular shape. A {110} crystal plane or a {111} crystal plane of the monocrystalline calcium fluoride is orthogonal to the center axis (A) of the tube.