The paper presents a photonic integrated circuit (PIC) concept for dual-band swept-source optical coherence tomography (SS-OCT). We designed the PIC for work with two swept sources with operation bands 820-880 nm and 1260-1360 nm. The PIC contains reference and sample arms and k-clocks for both bands. In both cases, k-clocks are unbalanced MachZehnder interferometers with a free spectral range greater or equal to the light sources’ operation bands. The PIC is developed for a silicon nitride manufacturing platform with minimum losses.
Vortex beams, characterized by a spiral phase distribution and bearing orbital angular momentum, have unique properties that make them valuable for the research and practical applications. Such beams are used in optical communications, optical manipulation, including tweezers, super-diffraction limit imaging, mode-division multiplexing, and quantum coding. This work investigates the dependence of the radiation flux density of an emitted optical vortex beam depending on the emitting structure geometry. A micro-ring resonator with etched holes is used as a vortex beam emitter. In our study, optimizing the width of the ring waveguide leads up to 30% for the resonant wavelength 1563 nm increase in the power flow density. In order to analyze how the whispering gallery modes are distributed in the cross-section of the ring waveguide, we enlarged the width of the ring waveguide from 400 nm to 500 nm. This approach can be applied to radiating micro-ring resonators in various applications.
Optoelectronic oscillator (OEO) output frequency stabilization in various use cases is urgent, especially for integrated photonics realizations. OEO environmental changes sensitivity limits the commercial use of this frequency generator type. In this article, we showed the application possibility of the tunable optical delay element for frequency stabilization. Also, we presented a mathematical model of the OEO with a tunable delay element for the output frequency control. We used Ansys Lumerical software for the mathematical model verification. The frequency tuning range is 2.6 GHz with a 50 MHz/ps frequency step.
This study presents a model of a fully connected neural network (NN) implemented on elements of integrated photonics, including the software implementation of this architecture. The main purpose was to compare the results of two NNs, for this reason the average correlation coefficient was calculated, which amounted to 0.9904. This indicates a high degree of similarity and accuracy between the model's performance on PC and photonics elements.
Intelligent systems significantly reduce routine work for doctors and improve diagnostic accuracy in medical diagnostics. However, the algorithms' effectiveness may be hindered by the heterogeneity of medical data and intermediate phases of a patient's clinical presentation. Additionally, not all intelligent systems can provide sufficient interpretability to analyze the clinical correlation between the system's responses and the actual clinical picture, thereby limiting their implementation in real medical practice. This article presents a solution for developing an intelligent algorithm to stage age-related macular degeneration of the fundus, a socially significant disease, including the challenging-to-detect intermediate stage, and an approach to visualize the algorithm's work in predicting disease stages. The algorithm's performance, developed based on a multimodal approach, was compared with deep neural networks and other multimodal approaches with commonly used data fusion algorithms. The comparison results demonstrate the elimination of the class imbalance effect due to the difficulty of detecting the intermediate disease stage, resulting in a reduction in the dynamic range of specificity and sensitivity values for all classes to no more than 5% for the developed approach. Moreover, the accuracy for the intermediate stage increased by 20% compared to existing commonly accepted data fusion algorithms.
High-frequency signal generators are required in such applications as telecommunications, radar, medical equipment, remote control, probing, radio astronomy, and spectroscopy. One can use an optoelectronic oscillator on a photonic integrated circuit in these applications due to its ease of implementation and low phase noise level. This article considers an optoelectronic oscillator with a phase shifter as a phase modulator implemented in a photonic integrated circuit to simplify the photonic integrated circuit design. The simulation results show that this system can generate microwave signals with a high signal-to-noise ratio (at least 35.27 dB). The side mode suppression ratio was up to 5.94 dB lower than the Mach-Zehnder modulator scheme. This proposed scheme can be used for microwave signal generation in various telecommunication applications and in interrogation tasks.
The article describes an approach to simulating a microring resonator structure on the silicon nitride integrated photonics platform when exposed to various hazardous to human health gases. We simulated various gases by changing the refractive index of the medium surrounding the resonator from 1 (vacuum) to 1.001768 (CCl4). The microring structure resonant wavelengths varied for various gases, and the quality factor, sensitivity, and intrinsic detection limit were determined. The simulation results show that it is possible to detect a wide range of gases hazardous to human health, including carbon tetrachloride, mercury vapor, carbon monoxide, and nitrogen monoxide, using the developed sensor. However, it is impossible to distinguish the last two gases based on the results of the current work using the SiN platform. Coatings are one of the potential ways to improve the designed sensor for detecting these gases.
This article analyzes the influence of the accuracy of manufacturing microring resonators on the characteristics of sensors based on silicon-on-insulator and silicon nitride platforms of integrated photonics. We estimated a deviation of 8 nm in increasing and decreasing the waveguide width. The results indicate that inaccuracies in the width of the waveguides lead to a resonant shift, but they do not affect the sensor’s sensitivity.
This paper analyzes the prospects for applying optical beams carrying orbital angular momentum (vortex beams) for sensing. We give short retrospectives on environmental properties one can measure with vortex beams, such as liquids turbulence, temperature, and movement. We also propose a new method based on photonic integrated circuits for determining liquids’ refractive index and turbulent properties using vortex beams. The essence of the method is to measure the refractive index and detect the vortex order simultaneously. The developing sensor consists of two microring resonators: a vortex emitter, which also acts as a refractive index-based temperature sensor, and a receiver. This method can potentially increase the measurements’ accuracy and measure the liquid’s turbulence.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.