Chip-Integrated Ti:Sapphire Laser With On-Chip Frequency Doubling

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Solution Overview

Problem

The high cost and large size of Titanium-doped sapphire lasers hinder their widespread integration and miniaturization, limiting their application in fields like two-photon microscopy, LIDAR systems, and quantum photonics, where a compact and affordable pulsed laser source is essential.

Innovation Solution

A fully chip-integrated Ti:Sapphire laser system is developed, utilizing a substrate with integrated waveguide resonators and a frequency doubler, capable of producing ultrafast pulses driven by an inexpensive infrared diode, reducing the system's size to a cubic centimeter or less and costing under $1000, with components like SiC ring resonators and Kerr nonlinear mirrors for efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional Ti:Sapphire laser system is used, then high-performance ultrafast pulsed laser output is achieved, but the system occupies large physical space and incurs high cost

Engineering Contradiction:
Improveultrafast pulsed laser performanceVSAvoidoptical table surface occupation
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges multiple discrete laser components (pump laser, Ti:Sapphire gain medium, optical cavities, mirrors) into a single integrated photonic chip structure. This consolidation maintains the functional performance of ultrafast pulsed laser generation while reducing the physical footprint from square meters to cubic millimeters, directly resolving the contradiction between performance and space occupation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs a nested architecture where the Ti:Sapphire gain medium is integrated within a waveguide resonator structure, which itself is embedded in a larger photonic chip platform. This nested design allows multiple functional elements to coexist in a compact volume, achieving high-performance laser operation in a minimal physical space.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If a traditional Ti:Sapphire laser system is used, then high-performance ultrafast pulsed laser output is achieved, but the system incurs prohibitively high cost

Engineering Contradiction:
Improveultrafast pulsed laser performanceVSAvoidsystem cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent creates a photonic chip copy of the traditional bulk laser system, replicating the essential optical functions (pumping, gain, resonance, frequency doubling) in a miniaturized integrated format. This copying approach enables the same ultrafast laser performance to be achieved at a fraction of the cost by using planar fabrication techniques instead of expensive custom-optics assembly.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent changes the operational parameters of the laser system by integrating it onto a photonic chip platform, which enables operation at lower pump powers and reduced material volumes. This parameter change from bulk to integrated operation dramatically reduces system cost while maintaining ultrafast pulse generation capability.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a traditional Ti:Sapphire laser system is used, then laser functionality is achieved, but the system size prevents widespread integration

Engineering Contradiction:
Improvelaser functionalityVSAvoidsystem volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent replaces the mechanical/optical bench-mounted laser system with an integrated photonic chip system that uses planar waveguides and on-chip resonators. This substitution eliminates the need for bulky optical tables, adjustment mechanisms, and discrete component mounting, reducing the system volume from cubic meters to cubic millimeters while preserving laser functionality.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If frequency-doubled Nd:YLF laser pumping is used, then Ti:Sapphire laser operation is achieved, but the overall system cost and complexity increase

Engineering Contradiction:
ImproveTi:Sapphire laser operationVSAvoidpump laser system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent designs the integrated photonic chip to perform multiple functions (pumping, frequency conversion, amplification, pulse generation) within a single device structure. This multi-functionality eliminates the need for separate pump laser systems and frequency doublers, reducing overall device complexity while maintaining Ti:Sapphire laser operation capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This miniaturization and cost reduction enable the integration of Ti:Sapphire lasers with on-chip photonics, enhancing applications such as two-photon microscopy, LIDAR, and quantum photonics by providing a low-cost, compact, and efficient ultrafast pulsed laser source.

Implementation Method 1

a first waveguide resonator composed of a gain medium integrated onto the substrate in a planar technology configuration; wherein the first waveguide resonator is optically coupled to the frequency doubler and is capable of producing laser radiation from pump diode light input

Methodology Applied
Scientific EffectOptical amplification: Laser

Implementation Method 2

a frequency doubler composed of a second order nonlinear material integrated onto the substrate in a planar technology configuration and as a resonant or waveguiding component; wherein the frequency doubler is optically coupled to the second waveguide resonator and is capable of producing frequency doubled radiation from the laser radiation

Methodology Applied
Scientific EffectSecond-harmonic generation: Second Harmonic Generation

Implementation Method 3

Titanium-doped sapphire (Ti:Sapphire) laser is unique among other commercially available lasers due to its very wide gain bandwidth. This enables Ti:Sapphire laser to be used as a wide-range (up to 650-1100 nm) tunable coherent source, and, consequently, as a source of ultra-fast pulsed light

Methodology Applied
Scientific EffectStimulated emission: Laser

Data Source

PatentEP4005039B1Chip-integrated titanium:sapphire laser
Publication Date: 2024.06.12 THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIV
  • EP4005039B1 patent drawingFigure 1A
  • EP4005039B1 patent drawingFigure 1B
  • EP4005039B1 patent drawingFigure 1C

AI summary

An integrated Ti: Sapphire laser device includes a substrate [100], a first waveguide resonator [102] composed of a gain medium integrated onto the substrate in a planar technology configuration, a frequency doubler [104] composed of a second order nonlinear material integrated onto the substrate in a planar technology configuration, and a second waveguide resonator [106] composed of a titanium doped sapphire gain medium integrated onto the substrate in a planar technology configuration.