Specific Wavelength Regions Research Articles

Deep-learning-based inverse design of colloidal quantum dots

Because optical properties of colloidal quantum dots (QDs) greatly depend on their layer thicknesses at the sub-nanometer scale, accurately predicting optical properties based on these structural parameters can help streamline the development process. However, most of traditional inverse design approaches require time-consuming numerical simulations and optimization processes. In this simulation-only paper, we propose a deep-learning-based inverse design model for colloidal InP/ZnSe/ZnS QDs based on the structure parameters of layer thicknesses and optical properties of the emission and absorption spectrum. Four different deep neural network (DNN) structures are implemented and compared. A tandem DNN structure with the simultaneous use of both emission and absorption spectra as input data shows the best accuracy due to its ability to alleviate the non-uniqueness problem in the inverse design of colloidal QDs. Our inverse design model enables the prediction of layer thicknesses for QDs that exhibit on-demand optical emission/absorption spectra, which are particularly enhanced at the specific target wavelength region. Moreover, the weights and biases of the well-trained tandem DNN for InP/ZnSe/ZnS QDs can be transferred and tuned to implement a transfer-learning-assisted inverse design model for CdSe/ZnSe/ZnS QDs, where the amount of training data to achieve the average prediction accuracy of 99.3 % is reduced by a maximum of 71.4 %.

Method for improving dry etching end point detection based on change in time accumulation correlation of plasma emitting wavelengths

This study proposes an optical emission spectroscopy (OES) analysis methodology to improve the ability to detect etching endpoints during high-level semiconductor plasma etching processes. Representative etching endpoint detection methods using single wavelength intensity or multiple wavelength intensity ratio changes include a low signal-to-noise ratio, high plasma instability, a small etching open area, and weak by-product emission signal problems due to deep etching under high-level process conditions such as high aspect ratio contact etching (HARC). As a result, it is difficult to detect the etching endpoint due to the very small or noisy change in the intensity over time due to the process progress of the wavelength selected by OES to detect the etching endpoint. In this study, a method of deriving an accumulative time correlation value according to process progress between selected wavelengths was developed by selecting all wavelengths observed in a specific wavelength region such as ultraviolet region in a spectrum emitted from plasma during a plasma etching process. After classifying the entire correlation signal groups derived as a pair of two intensity peak wavelengths into a dynamic time wrapping algorithm, the intensity change rate of the signal according to the process time was observed by selecting the signal with the most sensitive time change rate during the process. During the vertical nand flash memory manufacturing process, a test wafer for the purpose of detecting the etching endpoint was manufactured and evaluated under the conditions of the cell metal contact etching process, which is a high-level HARC etching process. As a result, it was confirmed that the signal selected by deriving the time accumulative correlation method had a high intensity change rate and a signal-to-noise ratio over time compared to a single wavelength or a plurality of wavelength ratio signals. The method proposed in this study is expected to contribute to process optimization by contributing to improving the ability to detect etching endpoints in high-level plasma etching processes in the future.

Developing a Portable Spectrometer to Detect Chemical Contaminants in Irrigation Water

Water pollution is a critical issue since it can severely affect health and the environment. The purpose of the study is to develop a portable spectrometer (ESP32-based spectrometer) to detect chemical contaminants in irrigation water by observing the light absorbance of contaminants. ESP32 and a light sensor (photodiode) were respectively, used as the main controller and detector of the portable spectrometer. It was developed based on optical dispersion and Beer–Lambert law theory. The light absorbance of different types of contaminants was displayed in a Blynk application for real-time monitoring. The samples were also tested using a lab-based spectroscopy method, ultraviolet-visible (UV-Vis) spectrometer. The spectral range of the measurement is from 350 nm to 700 nm and the standard error of the ESP32-based spectrometer is from 0.01 to 0.05. Five water samples were tested, consisting of ammonium nitrate, organic pesticide, zinc oxide and two different reservoirs used for irrigation. The absorption peaks of the ammonium nitrate and organic pesticide are 363 nm and 361 nm, respectively. Zinc oxide shows the absorbance peak at 405 nm, whereas both reservoirs show absorbance peaks lie in the region from 300 nm to 370 nm. Therefore, this study shows that different types of contaminants can absorb light only at specific wavelength regions by considering the concentration of samples. The developed ESP32-based spectrometer can be applied for on-site water quality monitoring as it is portable, light, simple and can be monitored in real time using multiple devices.

Perimeter-Area Soil Carbon Index (PASCI): modeling and estimating soil organic carbon using relevant explicatory waveband variables in machine learning environment

ABSTRACT Soil Organic Carbon (SOC) is the most important indicator of soil health and determines long-term crop productivity. Here, we applied the Random Forest regression model to soil hyperspectral data to determine the important spectral bands and regions for SOC retrieval. Multiple existing studies already identified specific wavelength bands that could be good indicators of SOC. However, there is no hyperspectral-based method that is currently available to simultaneously investigate these identified specific wavelength regions for SOC. To help fill this gap, we developed the Perimeter-Area Soil Carbon Index (PASCI) that utilized optimal SOC spectral bands and then evaluated its robustness for SOC prediction and retrieval against other existing indices. The results of regression analysis between SOC and PASCI values showed a significant relationship (r2 = 0.76; p < 0.05). A significant statistical relationship (r2 = 0.73) was also observed between SOC and the sum indices. The results from this study have advanced our understanding of the optimal spectral bands for SOC. Finally, the PASCI could be applied to hyperspectral and multispectral images to remotely quantify, predict, and map SOC.

Interrogation Method with Temperature Compensation Using Ultra-Short Fiber Bragg Gratings in Silica and Polymer Optical Fibers as Edge Filters.

The use of simpler and less bulky equipment, with a reliable performance and at relative low cost is increasingly important when assembling sensing configurations for a wide variety of applications. Based on this concept, this paper proposes a simple, efficient and relative low-cost fiber Bragg grating (FBG) interrogation solution using ultra-short FBGs (USFBGs) as edge filters. USFBGs with different lengths and reflection bandwidths were produced in silica optical fiber and in poly(methyl methacrylate) (PMMA) microstructured polymer optical fiber (mPOF), and by adjusting specific inscription parameters and the diffraction pattern, these gratings can present self-apodization and unique spectral characteristics suitable for filtering operations. In addition to being a cost-effective edge filter solution, USFBGs and standard uniform FBGs in silica fiber have similar thermal sensitivities, which results in a straightforward operation without complex equipment or calculations. This FBG interrogation configuration is also quite promising for dynamic measurements, and due to its multiplexing capabilities multiple USFBGs can be inscribed in the same optical fiber, allowing to incorporate several filters with identical or different spectral characteristics at specific wavelength regions in the same fiber, thus showing great potential to create and develop new sensing configurations.

Quantum Yield Measurements of Photochemical Reaction-Based Afterglow Luminescence Materials.

Afterglow materials have become one of the most promising luminescent materials due to their long luminescence lifetime. Photoluminescence quantum yield (PLQY), as one of the most fundamental and essential parameters of luminescent materials, can directly evaluate the luminescence properties of emissive compounds. Recently, a type of afterglow material based on a photochemical reaction has been developed. However, there is no suitable method to measure the PLQY of these afterglow materials due to their special luminescence principle. Herein, we present a method to measure the PLQY for these afterglow materials by collecting the luminescent dynamic curves of emission and excitation light at specific wavelength regions using a commercial spectrometer and an integrating sphere. We found that the emitted photons of this kind of afterglow material are in direct proportion to the excitation time, which means the PLQY is irrelevant to the excitation time.

Identification of specific wavelength regions for separating optically similar signals of coral reef benthic compositions

Identification of specific wavelength regions for separating optically similar signals of coral reef benthic compositions

Rapid Nondestructive Postharvest Potato Freshness and Cultivar Discrimination Assessment

Background: Quality and safety of potato is both cultivar and postharvest management dependent. The precise assessment of freshness and cultivar are complex tasks requiring time-consuming, expensive, and destructive techniques. Method: Potatoes from three commercial cultivars were stored for 5 months at 5 °C. Color and chlorophyll fluorescence were recorded, Red-Green-Blue (R-G-B), Red-Green-Near infrared (R-G-NIR) and Red-Blue-Near infrared (R-B-NIR) digital images, as well as hyperspectral images were acquired both on the external periderm of the tuber and in the inner flesh part. Partial least square regression (PLSR) and discriminant analysis, combined with feature selection techniques were implemented, in order to assess the potato freshness and to classify them into the respective genotypes. Results: The PLSR analysis of visible/near infrared (Vis/NIR) spectra reflectance most reliably predicted potato freshness, with a cross-validated regression coefficient equal to 0.981 and 0.947, as determined by external or internal measurements, respectively. Variance inflation factor, variable importance scores, and genetic algorithms identified specific wavelength regions that mostly affected the accuracy of the model in terms of strongest regression and lowest collinearity and root mean cross validation error. Conclusions: Vis/NIR spectra reflectance data from the skin of the potato tubers may be reliably used in the assessment of postharvest storage life, as well as in the cultivar discrimination process.

Mid-infrared spectroscopy of crystalline plagioclase feldspar samples with various Al,Si order and implications for remote sensing of Mercury and other terrestrial Solar System objects

We analyzed plagioclase feldspar samples that were well-characterized in terms of chemical composition as well as degree of Al,Si order in mid-infrared reflection spectra between 7 μm and 14 μm (1429 cm−1 and 714 cm−1). The chemical compositions were derived with an electron microprobe analyzer. To determine the degree of Al,Si order, powder X-ray diffraction methods were applied. For the interpretation of the infrared spectra, we used the wavelength of the Christiansen feature (CF) and the autocorrelation function for a specific wavelength region. The CF shifts from around 7.72 μm (1296 cm−1) in Na-richest samples to 8.10 μm (1234 cm−1) in the Ca-richest sample. Combining the CF position and the autocorrelation-derived value allowed to determine the degree of Al,Si order of the samples based on reflection spectra. The wavelength of the Transparency feature (TF) in the finest analyzed grain size fraction also depends on the chemical composition and the degree of Al,Si order. Our results are helpful for the interpretation of data returned by the MERTIS experiment onboard BepiColombo. The data help to distinguish between space weathering, shock effects, and ordering effects in plagioclase samples.

Design of tunable liquid laser based on presence of the conjugated-polymer counter influencing the spectral properties of the oligomer

Abstract In this paper, we studied the optical properties, lasing properties, and time-resolved spectroscopy (TRS) dynamics of the energy transfer between the conjugated oligomer (CO) 1,4-bis(9-ethyl-3-carbazo-vinylene)-9,9-dihexyl-fluorene (BECV-DHF) and conjugated-polymer (CP) influencer poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV) in a toluene environment. The oligomer 1,4-bis(9-ethyl-3-carbazo-vinylene)-9,9-dihexyl-fluorene (BECV-DHF) exhibits single amplified spontaneous emission (ASE) in a solution for a wide variety of concentration and solvent environment, but it produces dual ASE under the influence of MEH-PPV. The dual ASE of the oligomer is due to the interaction between these two laser materials, and it is studied using various spectroscopic techniques. The TRS showed that the presence of the CP in the CO solution does not change the excited state dynamics of the CO, and the fluorescence of the CO is quenched, and the fluorescence of CP is enhanced simultaneously; hence, the underlying mechanism could be modulation of the absorption band at specific wavelength region (460 ± 10 nm). Under an optical cavity (100%–60% reflectivity plane mirrors and with internal grating), a tunable laser with a 6 nm full width at half maximum (FWHM) from 560 nm to 580 nm and attenuation from 600 to 650 nm was observed. Spectrally narrow peaks were obtained at various wavelengths by changing the cavity mirror distance. This strategy of obtaining a laser tunable from 560 to 580 nm, in addition to dual ASE (436 nm and 464 nm), from a CP and CO blend could potentially facilitate the development of an efficient, low-cost laser.

Spectral dependence of third-order susceptibility of Au triangular nanoplates

We experimentally investigated the spectral dependence of the third-order susceptibility chi^{left( 3 right)} of Au triangular nanoplates in a broad wavelength region (400–1,000 nm). Complex shaped plasmonic nanoparticles provide a promising route to achieve control of their optical properties at the nanoscale. However, little is known about the effects of geometrical parameters to the optical nonlinearities and underlying mechanisms of the plasmon modes. Here, we obtained the chi^{left( 3 right)} of Au triangular nanoplates featuring a narrow plasmon resonance that is tunable in the visible and near-IR regions. This work demonstrates that the plasmonic triangular nanoplates simultaneously shows self-focusing and -defocusing, and saturable and reverse-saturable absorption properties at specific wavelength regions. Maximum amplitudes of real and imaginary components are − 6.8 × 10−18 m2/V2 at 668 nm and − 6.7 × 10−18 m2/V2 at 646 nm, respectively. Spectral dependence of the quantity chi^{left( 3 right)} enables comparison between different shaped plasmonic NPs to boost active plasmonic applications performance.

Violet-Blue Light Arrays at 405 Nanometers Exert Enhanced Antimicrobial Activity for Photodisinfection of Monomicrobial Nosocomial Biofilms.

Light-emitting diodes (LEDs) demonstrate therapeutic effects for a range of biomedical applications, including photodisinfection. Bands of specific wavelengths (centered at 405 nm) are reported to be the most antimicrobial; however, there remains no consensus on the most effective irradiation parameters for optimal photodisinfection. The aim of this study was to assess decontamination efficiency by direct photodisinfection of monomicrobial biofilms using a violet-blue light (VBL) single-wavelength array (SWA) and multiwavelength array (MWA). Mature biofilms of nosocomial bacteria (Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus) were grown on 96-well polypropylene PCR plates. The biofilms were then exposed to VBL for 2,700 s (SWA) and 1,170 s (MWA) to deliver 0 to 670 J/cm2, and the antibacterial activity of VBL was assessed by comparing the seeding of the irradiated and the nonirradiated biofilms. Nonirradiated groups were used as controls. The VBL arrays were characterized optically (spectral irradiance and beam profile) and thermally. The SWA delivered 401-nm VBL and the MWA delivered between 379-nm and 452-nm VBL, albeit at different irradiances and with different beam profiles. In both arrays, the irradiated groups were exposed to increased temperatures compared to the nonirradiated controls. All bacterial isolates were susceptible to VBL and demonstrated reductions in the seeding of exposed biofilms compared with the nonirradiated controls. VBL at 405 nm exerted the most antimicrobial activity, exhibiting reductions in seeding of up to 94%. Decontamination efficiency is dependent on the irradiation parameters, bacterial species and strain, and experimental conditions. Controlled experiments that ameliorate the heating effects and improve the optical properties are required to optimize the dosing parameters to advance the successful clinical translation of this technology.IMPORTANCE This study reports the efficacy of VBL and blue light (BL) and their antimicrobial activity against mature biofilms of a range of important nosocomial pathogens. While this study investigated the antibacterial activity of a range of wavelengths of between 375 and 450 nm and identified a specific wavelength region (∼405 nm) with increased antibacterial activity, decontamination was dependent on the bacterial species, strain, irradiation parameters, and experimental conditions. Further research with controlled experiments that ameliorate the heating effects and improve the optical properties are required to optimize the dosing parameters to advance the successful clinical translation of this technology.

Valuable Modern Strategy (ATR-IR) Spectroscopy Technique to Distinguish Between Normal and Lung Cancer Tissue

Background: Diagnosis of lung cancer is often delayed because most of the patients are asymptomatic during the primary cancer stages. Infrared spectroscopy is an improved technique compared with the others for identifying abnormal tissue types because of its spatial and spectral capabilities. Therefore, this study is taking an advanced advantage of the physical and optical properties of the attenuated total reflection Fourier-transform infrared system.Methods: The attenuated total reflection Fourier-transform infrared has been applied for cancer detection at infrared wavelengths that range from 4000-400 cm-1. This technique may be a beneficial diagnostic method because it uses the principles of physics, as optics and photonics with a specific wavelength region, which can make an immense difference.Results: The attenuated total reflection Fourier-transform infrared system spectra of normal lung tissue showed main peaks at 3321 and 1637 cm-1, which has been assigned to the OH and C=O function group of amide I and has intensities of approximately 61% (OH) and 76% (C=O). That intensity has been shown to decrease in the cancer tissue. A new peak at 1545 cm-1 appeared in the cancerous tissue, which could be an amide II.Conclusions: The identification of a biochemical component from either normal or cancerous lung tissue would help to evaluate malignant tissue. Thus, the obtained results indicated degradation of the biochemistry component (protein) of the tissue due to carcinogenic disease.

Design and Optimization of Novel ZnS–Metal Core-Shell Random Structures for Light Harvesting—a Computational Study

We present a systematic computational study on the optical properties of a new composite structure based on ZnS–metal core-shell particles, which can find applications in light trapping. Three metals Au, Ag and Cu whose surface plasmon resonance (SPR) fall in visible region are used as shell materials. Effect of shell material, thickness and core radius on the SPR values is studied using Mie theory. Optimization of aspect ratios for each composite is done for maximum extinction in visible region. Uniform random distribution of selected particles with optimized aspect ratios is modelled using Lumerical FDTD software. Transmission of wavelengths 400, 450, 500, 550, 600 and 650 nm through random media is investigated using finite difference time domain simulations. Shell material is found to have a large influence on light trapping ability of the composite. Depending on the shell material, thickness and core radius, wavelengths at different regions of visible spectrum can be trapped, thus offering scope for designing novel light harvesting systems tunable over specific wavelength regions.

DC펄스 스퍼터링 공정 변수가 다층 박막의 광 반사율에 미치는 영향

특정 광 파장 영역대역에서 광 반사율을 갖는 다층 박막을 DC펄스 스퍼터링 공정으로 제작하기 위하여 공정변수가 다층 박막의 광학 특성에 미치는 영향이 연구되었다. 다층 박막 필름을 제작하기위한 시뮬레이션이 이루어졌으며, DC펄스 스퍼터링 공정을 이용한 저 굴절률의 <TEX>$SiO_2$</TEX>와 고 굴절률의 <TEX>$TiO_2$</TEX> 박막의 광학 특성에 미치는 공정 변수 파라미터가 연구되었다. DC펄스 스퍼터링 파워 2kW, 아르곤 가스 200sccm(standard cubic centimeter per minute)기준조건에서 산소가스 비율 12% 범위에서 제작한 <TEX>$SiO_2$</TEX>박막은 굴절률 1.46이었고 산소가스 1% 비율에서 제작한 <TEX>$TiO_2$</TEX>박막은 굴절률 2.27이었다. 이들 박막으로 구성된 고 굴절률 박막/저 굴절률 박막/고 굴절률 박막의 3층 다층 박막 구조의 광학설계 시뮬레이션 결과와 측정된 광 반사율 특성결과는 파장 대역에 걸쳐 유사한 경향이 있는 것으로 측정되었다. 근적외선 780nm에서 1200nm파장 대역 영역에서 광 반사율 45%이상의 성능을 갖는 다층 박막 필름을 제작할 수 있었고 근적외선 차단 기능 박막으로 사용될 것으로 기대된다. The process parameters of DC pulsed sputtering to produce a multi-layer thin film with light reflectance at a specific wavelength region were studied. The optical simulation of multi-layer thin films of the silicon dioxide (<TEX>$SiO_2$</TEX>) films with a low refractive index and the titanium dioxide (<TEX>$TiO_2$</TEX>) films with a high refractive index was done. Under a DC pulsed sputtering power of 2kW and 200 sccm(standard cubic centimeter per minute) argon gas, the silicon dioxide films with a refractive index of 1.46 in the range of oxygen gas ratios of 12% and a titanium dioxide film with a refractive index of 2.27 in the range of oxygen gas ratios of 1% were produced. The multi-layer structure of high refractive index/low refractive index/high refractive index was designed and fabricated. The characteristics of the fabricated multi-layer thin film structure showed a reflectance of more than 45% in the range, 780 to 1200nm. This multi-layer structure is expected to be used to block the near infrared wavelength light.

Efficiency enhancement and angle-dependent color change in see-through organic photovoltaics using distributed Bragg reflectors

A distributed Bragg reflector (DBR) is conducted as a bottom reflector in see-through organic photovoltaics (OPVs) with an active layer of poly(3-hexylthiophene) and phenyl-C61-butyric acid methyl ester (P3HT:PCBM). The DBR consists of alternative layers of the high- and low-refractive index materials of Ta2O5 (n = 2.16) and SiO2 (n = 1.46). The DBR selectively reflects the light within a specific wavelength region (490 nm–630 nm) where the absorbance of P3HT:PCBM is maximum. The see-through OPVs fabricated on DBR exhibit efficiency enhancement by 31% compared to the device without DBR. Additionally, the angle-dependent transmittance of DBR is analysed using optical simulation and verified by experimental results. As the incident angle of light increases, peak of reflectance shifts to shorter wavelength and the bandwidth gets narrower. This unique angle-dependent optical properties of DBR allows the facile color change of see-through OPVs.

Molecular genetic response to varied wavelengths of light in Xiphophorus maculatus skin

Xiphophorus fishes represent a model often utilized to study UVB induced tumorigenesis. Recently, varied genetic responses to UVB exposure have been documented in the skin of female and male Xiphophorus, as have differences in UVB response in the skin of different parental species and for interspecies hybrids produced from crossing them. Additionally, it has been shown that exposure to “cool white” fluorescent light induces a shift in the genetic profiles of Xiphophorus skin that is nearly as robust as the UVB response, but involves a fundamentally different set of genes. Given these results and the use of Xiphophorus interspecies hybrids as an experimental model for UVB inducible melanoma, it is of interest to characterize genes that may be transcriptionally modulated in a wavelength specific manner.The global molecular genetic response of skin upon exposure of the intact animal to specific wavelengths of light has not been investigated. Herein, we report results of RNA-Seq experiments from the skin of male Xiphophorus maculatus Jp 163 B following exposure to varied 50nm wavelengths of light ranging from 300–600nm. We identify two specific wavelength regions, 350–400nm (88 genes) and 500–550nm (276 genes), that exhibit transcriptional modulation of a significantly greater number of transcripts than any of the other 50nm regions in the 300–600nm range. Observed functional sets of genes modulated within these two transcriptionally active light regions suggest different mechanisms of gene modulation.

Effective light trapping by hybrid nanostructure for crystalline silicon solar cells

Ag nanoparticles (NPs), as etching catalyst, are applied onto the pyramid textured surface of the semi-finished single crystalline silicon solar cell by spraying a solution containing AgNO3 and sodium citrate. Upon chemical etching, nanopits are formed with the Ag NPs staying inside of the nanopits. Complete solar cells with and without the Ag-assisted etching are fabricated to study the effects of the hybrid nanostructure. It is found that the optical reflection is effectively reduced by the nanostructure and the incident light is harvested more effectively for enhanced external quantum efficiency (EQE) by as much as 17% for the cells before the SiNx anti-reflection coating, and the EQE can be further enhanced by applying an electric bias 1V during the EQE measurement. It is believed that when the solar cell with the Ag NPs is illuminated, the local surface plasmon resonance (LSPR) is induced at the specific wavelength regions around 405 and 810nm. For ultraviolet light, the LSPR effect dominates the increases of the EQE while the effective medium effect is also believed to be responsible for the effective light trapping.

Enhanced Photo Current in n-ZnO/p-Si Diode Via Embedded Ag Nanoparticles for the Solar Cell Application

In this study, an n-ZnO/p-Si heterojunction diode with embedded Ag nanoparticles was fabricated to investigate the possible improvement of light trapping via the surface plasmon resonance effect for solar cell applications. The Ag nanoparticles were fabricated by the physical sputtering method. The acquired current-voltage curves and optical absorption spectra demonstrated that the application of Ag nanoparticles in the n-ZnO/p-Si interface increased the photo current, particularly in specific wavelength regions. The results indicate that the enhancement of the photo current was caused by the surface plasmon resonance effect generated by the Ag nanoparticles. In addition, minority carrier lifetime measurements showed that the recombination losses caused by the Ag nanoparticles were negligible. These results suggest that the embedding of Ag nanoparticles is a powerful method to improve the performance of n-ZnO/p-Si heterojunction solar cells.

Elucidating the origin of spurious modes in aluminum nitride microresonators using a 2-D finite-element model.

In this work, an approach has been developed to predict the location of large spurious modes in the resonant response of aluminum nitride (AlN) microelectromechanical systems (MEMS) resonators over a wide range of desired operating frequencies. This addresses significant challenges in the design of more complex AlN devices, namely the prediction and elimination of spurious modes in the resonance response. Using the finite element method (FEM), the dispersion curves at wavelengths ranging from 8 to 20 μm were computed. It was determined that the velocities of symmetric Lamb (S0) and high-order antisymmetric (A) modes overlap at specific wavelengths. A 2-D FEM analysis showed that both the S0 and higher order A modes are mutually excited at a common operating wavelength. From this analysis, the coupling-of-modes (COM) parameters were extracted and used to compute the P-matrix and S-parameters using a 6-port transmission matrix. The P-matrix simulation was able to predict the electrical response of the S0 and nearby spurious modes. This work identified specific wavelength regions where COM has limited accuracy because of mode conversion. In these regions, the reflection (κ(p)) and transduction (ζ(p)) parameters change rapidly.