Diamond Structures for Tuning of the Finesse Coefficient of Photonic Devices
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2022-03-31 |
| Journal | Materials |
| Authors | Monika Kosowska, A.K. Mallik, MichaĆ Rycewicz, Ken Haenen, MaĆgorzata Szczerska |
| Institutions | GdaĆsk University of Technology, Bydgoszcz University of Science and Technology |
| Analysis | Full AI Review Included |
Diamond Structures for Tuning of the Finesse Coefficient of Photonic Devices
Section titled âDiamond Structures for Tuning of the Finesse Coefficient of Photonic DevicesâAnalysis of: Kosowska et al., Diamond Structures for Tuning of the Finesse Coefficient of Photonic Devices, Materials 2022, 15, 2552.
This document analyzes the application of MPCVD diamond structures (Boron-Doped, Nitrogen-Doped, and Nanocrystalline) in tailoring the Finesse Coefficient (F) of Fabry-Perot (FP) fiber-optic sensors. The findings directly validate 6CCVDâs core capability in providing highly customized, doped, and precision-polished diamond materials for advanced optoelectronic and sensing applications.
Executive Summary
Section titled âExecutive SummaryâThe following points summarize the core technical achievements and the value proposition for engineers utilizing 6CCVD materials:
- Tunable Finesse via Doping: The research successfully demonstrated that the Finesse Coefficient (F) of a Fabry-Perot cavity can be precisely tuned by selecting different CVD diamond structures (BDD, N-doped, NCD).
- Mechanism of Control: Tailoring the dopant element (Boron or Nitrogen) and dopant level during the MPCVD process alters the refractive index ($n$), which directly controls the mirror reflectivity ($R$) and, consequently, the cavity finesse.
- Wide Finesse Range Achieved: Finesse coefficients were demonstrated across a wide range, from low finesse (F=0.3094 for BDD) suitable for robust two-beam approximation, up to high finesse (F=4.4383 for NCD/Ag hybrid) suitable for precise spectroscopy.
- Robust Sensor Design: CVD diamond films provide superior mechanical and chemical immunity, biocompatibility, and prolonged lifespan, making them ideal reflective surfaces for challenging opto-electrochemical sensing environments.
- MPCVD Validation: The study confirms that MPCVD is the essential fabrication method for creating diamond structures with tailored optical properties necessary for advanced photonic devices.
- Application Focus: This tuning capability is critical for optimizing opto-electrochemical setups, allowing the optical parameters of the resonator to be matched to the optical properties of the investigated liquid solutions.
Technical Specifications
Section titled âTechnical SpecificationsâThe following table extracts key performance indicators and material parameters demonstrated in the research:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Operating Wavelength | 1550 | nm | Central wavelength of broadband light source |
| Finesse Coefficient (BDD) | 0.3094 | - | Boron-doped diamond film (Lowest Finesse) |
| Finesse Coefficient (N-doped) | 0.3653 | - | Nitrogen-doped diamond film |
| Finesse Coefficient (NCD + Ag) | 4.4383 | - | Nanocrystalline diamond sheet with silver mirror (Highest Finesse) |
| Cavity Length (BDD) | 100 | ”m | Experimental setup B |
| Cavity Length (N-doped) | 150 | ”m | Experimental setup C |
| Cavity Length (NCD + Ag) | 180 | ”m | Experimental setup D |
| Minimal Transmittance (BDD) | 0.7637 | a.u. | Corresponds to F=0.3094 |
| Minimal Transmittance (NCD + Ag) | 0.2253 | a.u. | Corresponds to F=4.4383 |
| Reflectivity Formula | R = ((n1 - n2) / (n1 + n2))2 | - | Reflectivity dependence on refractive indices |
Key Methodologies
Section titled âKey MethodologiesâThe experimental success relies heavily on precise material synthesis and integration, achievable through advanced MPCVD techniques:
- Material Synthesis: Diamond structures (Boron-Doped Diamond (BDD), Nitrogen-Doped Diamond, and Nanocrystalline Diamond (NCD) sheets) were produced using a Microwave Plasma-Assisted Chemical Vapor Deposition (MPCVD) system.
- Property Tailoring: The optical properties (refractive index, $n$) of the diamond films were tailored by adjusting CVD process parameters, specifically the dopant element (Boron or Nitrogen) and the dopant level.
- Morphology Characterization: Surface morphology, crystallite size, and uniformity were investigated using Scanning Electron Microscopy (SEM) to ensure suitability for FP cavity construction.
- Cavity Construction: A fiber-optic Fabry-Perot interferometer was built in a reflective mode, utilizing a polished fiber end-face as the first mirror (M1) and the custom diamond structure as the second mirror (M2).
- Interferometer Setup: The setup employed a micromechanical system for proper positioning and stabilization, ensuring the reflective surfaces were parallel and allowing the air-gap cavity length to be adjusted from 0 to 1 mm.
- Optical Measurement: The transmission functions were measured using a broadband light source centered at 1550 nm and analyzed via an optical spectrum analyzer.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the high-quality, customized MPCVD diamond materials required to replicate, optimize, and extend this research into commercial photonic and opto-electrochemical devices. Our capabilities ensure precise control over the material parameters necessary for finesse tuning.
| Research Requirement | 6CCVD Solution & Capability | Technical Advantage |
|---|---|---|
| Boron-Doped Diamond (BDD) Films | Heavy Boron Doped PCD/SCD | We offer precise control over Boron doping concentration, enabling accurate tuning of the refractive index ($n$) and reflectivity ($R$) for specific low-finesse applications (e.g., robust two-beam sensors). |
| Nitrogen-Doped Films | N-Doped Optical Grade PCD/SCD | Available for tuning finesse in the intermediate range, providing flexibility for various sensing modalities. |
| Nanocrystalline Diamond (NCD) | High-Quality Polycrystalline Diamond (PCD) | Custom wafers up to 125mm diameter. Ideal for large-area sensor construction or high-finesse configurations requiring robust, uniform films. |
| Surface Quality & Microroughness | Precision Polishing Services | SCD polished to Ra < 1nm; Inch-size PCD polished to Ra < 5nm. This minimizes scattering, non-parallelism losses, and defects, which are critical factors impacting FWHM and overall finesse stability. |
| Custom Cavity Interfaces | In-House Metalization Services | Capability to deposit Au, Pt, Pd, Ti, W, Cu. This allows researchers to integrate highly reflective layers (like the Ag mirror used in the NCD hybrid configuration) directly onto the diamond structure for complex, high-finesse FP designs. |
| Custom Dimensions & Thickness | Full Customization (Plates/Wafers) | SCD/PCD films available from 0.1”m to 500”m thickness, and substrates up to 10mm. We can match the exact dimensions required for compact fiber-optic sensor integration and micromechanical setups. |
| Global Supply Chain | Global Shipping (DDU/DDP) | Reliable, fast delivery of custom diamond materials worldwide, ensuring project timelines are met regardless of location. |
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD team specializes in the relationship between MPCVD growth parameters and the resulting optical, electrochemical, and mechanical properties of diamond. We offer consultation services to assist researchers in selecting the optimal material (SCD, PCD, or BDD) and specification (doping level, thickness, polishing grade) required for similar opto-electrochemical sensing projects or high-precision Fabry-Perot cavity development.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Finesse coefficient is one of the most important parameters describing the properties of a resonant cavity. In this research, a mathematical investigation of the application of diamond structures in a fiber-optic Fabry-Perot measurement head to assess their impact on the finesse coefficient is proposed. We present modeled transmission functions of cavities utilizing a nitrogen-doped diamond, a boron-doped diamond, nanocrystalline diamond sheet and a silver mirror. The diamond structures were deposited using a microwave plasma-assisted chemical vapor deposition system. A SEM investigation of surface morphology was conducted. The modeling took into consideration the fiber-optic Fabry-Perot setup working in a reflective mode, with an external cavity and a light source of 1550 nm. A comparison of the mathematical investigation and experimental results is presented.
Tech Support
Section titled âTech SupportâOriginal Source
Section titled âOriginal SourceâReferences
Section titled âReferencesâ- 2018 - Hybrid Optoelectrochemical Sensor for Superselective Detection of 2,4,6-Trinitrotoluene Based on Electrochemical Reduced Meisenheimer Complex [Crossref]
- 2020 - Nanopaper-Based Screen-Printed Electrodes: A Hybrid Sensing Bioplatform for Dual Opto-Electrochemical Sensing Applications [Crossref]
- 2013 - Toward Optical Sensors: Review and Applications [Crossref]
- 2019 - Multiparameter Fiber-Optic Sensors: A Review [Crossref]
- 2019 - Distributed Optical Fiber Sensing: Review and Perspective [Crossref]
- 1992 - Optical Fiber Sensing with a Low-Finesse Fabry-Perot Cavity [Crossref]