Effect of temperature change on refractive index of an egg white and yolk - a preliminary study
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2022-07-01 |
| Journal | Photonics Letters of Poland |
| Authors | Patryk SokoĆowski |
| Institutions | GdaĆsk University of Technology |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Diamond for High-Precision Fabry-Perot Sensing
Section titled âTechnical Documentation & Analysis: Diamond for High-Precision Fabry-Perot SensingâExecutive Summary
Section titled âExecutive SummaryâThis research demonstrates the use of a fiber-optic Fabry-Perot Interferometer (FPI) for high-resolution measurement of refractive index (RI) changes in biological samples (egg white and yolk) as a function of temperature (30-47°C).
- Application: High-sensitivity optical sensing of biological fluid properties, relevant for quality control and biomedical diagnostics.
- Methodology: FPI sensor constructed using a polished fiber end-face and a reflective surface (aluminum dish).
- Critical Parameters: Precise control over the geometrical cavity length (L), measured between 211.7 ”m and 238.8 ”m, is essential for accurate RI calculation.
- Material Requirement: The sensor relies on a highly stable, reflective surface. 6CCVDâs MPCVD diamond substrates offer superior thermal stability, chemical inertness, and ultra-low surface roughness (Ra < 1 nm for SCD) compared to standard materials, significantly enhancing FPI visibility and sensitivity.
- Wavelength Compatibility: Measurements were conducted at 1550 nm, a region where 6CCVDâs optical grade Single Crystal Diamond (SCD) exhibits excellent transparency and low absorption.
- 6CCVD Value Proposition: We provide custom-thickness SCD and PCD wafers, precisely polished and metalized, ideal for replicating or advancing this FPI sensor design into a robust, thermally stable diamond platform.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the research paper detailing the FPI sensor configuration and measurement results:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Central Wavelength (λ) | 1550 | nm | Superluminescent Diode (SLD) source |
| SLD Spectral Width | 35 | nm | Source bandwidth for interference generation |
| Measurement Temperature Range | 30 - 47 | °C | Biological sample testing range |
| Estimated Cavity Length (Egg White) | 238.8 | ”m | Geometrical path length (L) |
| Estimated Cavity Length (Egg Yolk) | 211.7 | ”m | Geometrical path length (L) |
| Reference RI (Air) | 1.0003 | N/A | Used for initial cavity length estimation at 1550 nm |
| Observed RI Range (Egg White) | ~1.1 to 1.3 | N/A | Refractive index variation with temperature |
| Observed RI Range (Egg Yolk) | ~1.2 to 1.7 | N/A | Refractive index variation with temperature |
| Sensor Type | Fabry-Perot Interferometer (FPI) | N/A | Used for high-resolution RI measurement |
Key Methodologies
Section titled âKey MethodologiesâThe experiment utilized a fiber-optic FPI sensor head coupled with a heat plate and an Optical Spectrum Analyzer (OSA) to monitor spectral shifts.
- Sensor Construction: The FPI measurement head was built using a polished fiber end-face and an aluminum weighing dish acting as the reflective surface.
- Equipment Configuration: The setup included an Ando AQ6319 Optical Spectrum Analyzer, an SLD (1550 ± 20 nm), a 2:1 fiber coupler, and a custom heat plate.
- Cavity Length Calibration: The geometrical cavity length (L) was first estimated by measuring the interference spectrum of air at room temperature, using the known RI of air (1.0003 at 1550 nm).
- Sample Preparation: Free-range eggs were separated into white and yolk, and small volumes (few milliliters) were placed on the aluminum weighing dish.
- Temperature Cycling: Measurements were performed across a temperature range of 30°C to 47°C, with precise 1°C steps, using the heat plate.
- RI Calculation: The refractive index (n) of the sample was calculated based on the estimated cavity length (L) and the measured interference signal spectrum (specifically, the distance between adjacent maxima, λ1 and λ2).
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe FPI sensor design requires materials with exceptional optical quality, precise thickness control, and high thermal stabilityâareas where 6CCVDâs MPCVD diamond excels. Replacing the aluminum dish with a diamond substrate significantly enhances sensor performance, longevity, and chemical resistance, especially for biological applications.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend this high-precision FPI sensing research, 6CCVD recommends the following materials:
- Optical Grade Single Crystal Diamond (SCD): Ideal for the reflective substrate. SCD offers superior thermal conductivity (minimizing temperature gradients across the sensor head) and excellent optical transparency in the 1550 nm range.
- Benefit: SCD provides an ultra-stable platform for high-resolution optical measurements.
- Optical Grade Polycrystalline Diamond (PCD): Recommended for applications requiring larger sensor areas (up to 125 mm diameter) or where cost is a primary constraint, while still offering significantly better thermal and chemical properties than aluminum.
- Polishing Specification: To maximize FPI fringe visibility and minimize scattering losses, 6CCVD guarantees Ra < 1 nm polishing on SCD and Ra < 5 nm on inch-size PCD wafers.
Customization Potential
Section titled âCustomization PotentialâThe success of this FPI sensor hinges on precise control of the cavity length (L) and the quality of the reflective surface. 6CCVD provides the necessary customization to optimize this design:
| Requirement from Paper | 6CCVD Customization Capability | Technical Advantage |
|---|---|---|
| Precise Cavity Length (L â 211-239 ”m) | Custom Thickness Control: We supply SCD and PCD plates in the critical thickness range of 0.1 ”m to 500 ”m. | Allows the diamond substrate itself to define the precise geometrical path length (L) or act as a highly stable spacer. |
| Reflective Surface | Custom Metalization: We offer in-house deposition of highly reflective and chemically inert layers (e.g., Au, Pt, Ti/Au stack). | Replaces the standard aluminum dish with a robust, bio-compatible, and highly stable reflective diamond surface, improving sensor longevity and signal-to-noise ratio. |
| Sensor Integration | Custom Dimensions & Shaping: Plates/wafers available up to 125 mm diameter. Custom laser cutting and shaping services are available for integration into complex fiber-optic setups. | Ensures seamless integration of the diamond element into existing FPI sensor housing and heat plate configurations. |
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house PhD team specializes in applying diamond materials to advanced photonics and sensing applications. We can assist researchers in transitioning from preliminary studies using standard materials (like aluminum) to robust, high-performance diamond platforms.
We offer consultation on material selection, surface preparation, and metalization schemes specifically tailored for high-resolution Fabry-Perot Interferometry (FPI) projects, ensuring optimal thermal management and chemical compatibility for biological sensing.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly. We ship globally (DDU default, DDP available).
View Original Abstract
In this article, the refractive index of an egg white and yolk depending on temperature in range 30 - 47 °C over 1550 nm was determined. The measurement head was constructed as fiber optic Fabry-Perot interferometer with interference between polished fiber end-face and aluminum weighing dish. The measurement setup has been made of an optical spectrum analyzer, a superluminescent diode with a central wevelength of 1550 nm, 2:1 fiber coupler and heat plate. Full Text: PDF ReferencesP. Magdelaine, âEgg and egg product production and consumption in Europe and the rest of the world, Improving the Safety and Quality of Eggs and Egg Productsâ, Egg Chemistry, Production and Consumption, 3 (2011). CrossRef H. Kuang, F. Yang, Y. Zhang, T. Wang, and G. Chen, âThe Impact of Egg Nutrient Composition and Its Consumption on Cholesterol Homeostasisâ, Cholesterol (2018). CrossRef J. Gienger, K. Smuda, R. MĂŒller, M. BĂ€r, and J. Neukammer, âRefractive index of human red blood cells between 290 nm and 1100 nm determined by optical extinction measurementsâ, Sci. Rep. 9, 1 (2019). CrossRef P. Listewnik, M. Hirsch, P. Struk, M. Weber, M. Bechelany, and M. JÄdrzejewska-Szczerska, âPreparation and Characterization of Microsphere ZnO ALD Coating Dedicated for the Fiber-Optic Refractive Index Sensorâ, Nanomaterials 9, 2 (2019) CrossRef Y. Wu, Y. Zhang, J. Wu, and P. Yuan, âFiber-Optic Hybrid Structured Fabry-Perot Interferometer Based On Large Lateral Offset Splicing for Simultaneous Measurement of Strain and Temperatureâ, J. Lightwave Technol., 35, 19 (2017). CrossRef M. Islam, M. Mahmood, M Lai, K. Lim, and H. Ahmad, âChronology of Fabry-Perot Interferometer Fiber-Optic Sensors and Their Applications: A Reviewâ, Sensors 14, 4 (2014). CrossRef K. Karpienko, M. WrĂłbel, and M. JÄdrzejewska-Szczerska, âDetermination of refractive index dispersion using fiber-optic low coherence Fabry-Perot interferometer: implementation and validationâ, Opt. Eng. 53, 7 (2014). CrossRef M. Kosowska, D. Majchrowicz, K. Sankaran, M. Ficek, K. Haenen, and M. Szczerska, âDoped Nanocrystalline Diamond Films as Reflective Layers for Fiber-Optic Sensors of Refractive Index of Liquidsâ, Materials 12, 13 (2019). CrossRef G. Xiao, A. Adnet, Z. Zhang, F. Sun, and C. Grover, âMonitoring changes in the refractive index of gases by means of a fiber optic Fabry-Perot interferometer sensorâ, Sensors and Actuators 118, 2 (2005). CrossRef