Hollow-Core Photonic Crystal Fiber Density Control

Solution Overview

Problem

Current lithographic technologies face challenges in generating broadband radiation with controlled wavelength properties and conversion efficiency, particularly for ultraviolet, deep ultraviolet, and extreme ultraviolet ranges, due to uniform fiber properties which affect dispersion and nonlinear processes.

Innovation Solution

A hollow-core photonic crystal fiber assembly with a density control system that adjusts the medium's density profile along its length to establish a desired zero dispersion wavelength profile, enabling efficient conversion of input radiation to broadband radiation, including supercontinuum generation, by modulating instability and enhancing soliton-trapping and dispersive wave interactions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If uniform fiber properties are used, then the fiber structure is simple and easy to manufacture, but the dispersion control and conversion efficiency deteriorate

Engineering Contradiction:

Improvefiber manufacturing simplicityVSAvoiddispersion wavelength control precision

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating a density gradient within the fiber core, where the density varies spatially from the center to the periphery. This non-uniform density distribution enables different regions of the fiber to provide different dispersive properties, allowing precise control of the zero dispersion wavelength profile along the fiber length while maintaining a relatively simple overall fiber structure that can be manufactured using standard techniques.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by modifying the density parameter of the fiber core material to establish a desired zero dispersion wavelength profile. By controlling the density distribution (e.g., through controlled doping or compositional gradients), the patent achieves precise dispersion management and enhances broadband radiation generation efficiency without requiring complex fiber geometric structures.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If the wavelength range is extended, then the broadband radiation capability is improved, but the intensity distribution uniformity deteriorates

Engineering Contradiction:

Improvewavelength range coverageVSAvoidintensity distribution uniformity

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by creating a density gradient within the fiber core, where the density varies spatially from the center to the periphery. This non-uniform density distribution enables different regions of the fiber to provide different dispersive properties, allowing precise control of the zero dispersion wavelength profile along the fiber length while maintaining a relatively simple overall fiber structure that can be manufactured using standard techniques.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by modifying the density parameter of the fiber core material to establish a desired zero dispersion wavelength profile. By controlling the density distribution (e.g., through controlled doping or compositional gradients), the patent achieves precise dispersion management and enhances broadband radiation generation efficiency without requiring complex fiber geometric structures.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution extends the wavelength range of generated broadband radiation, improves conversion efficiency, and achieves more uniform intensity distribution across the spectrum, particularly for shorter wavelengths, enhancing the capabilities of metrology and lithographic applications.

Implementation Method 1

converting input radiation to broadband radiation, including supercontinuum generation, by modulating instability

Methodology Applied

Scientific EffectModulation instability:

Implementation Method 2

enhancing soliton-trapping and dispersive wave interactions

Methodology Applied

Scientific EffectSoliton-trapping: Soliton

Implementation Method 3

controlling a density profile of the medium along at least a part of the length of the fiber to establish a desired zero dispersion wavelength profile

Methodology Applied

Scientific EffectDispersion control: Dispersion (of waves)

Implementation Method 4

a micro-structured fiber with a hollow core extending along a length of the fiber

Methodology Applied

Scientific EffectPhotonic crystal effect: Photonic Crystal

Data Source

PatentEP3851904B1Method, assembly, and apparatus for improved control of broadband radiation generation

Publication Date: 2023.02.01 ASML NETHERLANDS BV

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AI summary

A hollow-core photonic crystal fiber (HC-PCF) assembly for converting input radiation to broadband radiation, the hollow core fiber assembly comprising: a micro-structured fiber with a hollow core extending along a length of the fiber from an input end configured to receive input radiation to an output end configured to output broadband radiation, wherein the hollow core of the fiber is configured to comprise a medium; and a density control system configured to control a density profile of the medium along at least a part of the length of the fiber to establish a desired zero dispersion wavelength profile along at least a part of the length of the fiber.