A Laser Written 4D Optical Microcavity for Advanced Biochemical Sensing in Aqueous Environment

Tcherniavskaia

Advanced Photonics Research

et al. 2021

Self Cite

Although machine learning (ML) solutions are conquering science and technology with a growing number of the affected branches, only a few examples have been demonstrated so far to boost the highly sensitive and label‐free optical detectors. Nevertheless, ML methods can indeed provide novel strategies for emerging optical sensing technologies to overcome the challenges of real‐world implementation. On this way, the sensing techniques become intelligent self‐learning systems capable for predictions of the probed parameters in an automated and self‐adjusting manner. Herein, a report on the upgraded ML engine of an affordable multiresonator imaging sensor operating at a fixed frequency is provided. It is demonstrated for the first time that such a sensor supplemented by a long short‐term memory (LSTM) network processing engine enables accurate prediction of the dynamical sensor responses already within the early stages of the observed variations. On example of the experimental data of solutions mixing dynamics, the possibility for accurate (>95%) differentiation of the dynamical variations at the refractive index level of 5.5 × 10−4 within a six times shorter period than the whole time series is shown. The impact of the parameters and architecture of the LSTM‐based processing engine on the speed and prediction accuracy is analyzed.

“…Still, a more complex behavior of the dynamical variations of the spectral shift can be observed for microresonators with functional layers or with structural response enhancement. [ 11 ]…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Intelligent Optical Microresonator Imaging Sensor for Early Stage Classification of Dynamical Variations

Tcherniavskaia

Advanced Photonics Research

et al. 2021

Self Cite

“…Polymeric microresonators with several geometries have been fabricated by TPP, including toroids [ 124 ], disks [ 125 , 126 , 127 ], cylinders [ 17 , 128 ], rings [ 26 , 51 , 129 ], and spheres [ 130 ]. Moreover, the flexibility of geometry afforded by this technique allows the fabrication of suspended parts ( Figure 12 a,c), varying the height of structures on the same chip ( Figure 12 b), and wire bonding fiber-to-chip coupling elements ( Figure 12 d and Ref.…”

Section: Devices Fabricated Via Tpp: General Applicationsmentioning

confidence: 99%

“…WGM microresonators fabricated by TPP can achieve Q-factors, in the near-infrared, from 10 2 until 10 6 ) [ 124 , 125 , 138 , 139 , 140 ]. Since the WGMs are strongly confined to the microresonator’s edge, the Q-factor in such structures is primarily limited by light scattering at the microresonator surface.…”

Section: Devices Fabricated Via Tpp: General Applicationsmentioning

confidence: 99%

“…However, it can be challenging to accomplish more confined geometries, such as spheres, toroids, or even disks and integrated microrings, with smooth surfaces by TPP. Indeed, the Q-factor of microresonators with spherical [ 130 ] and toroid-like [ 124 ] geometries is in the order of

or lower, and the Q-factor of integrated microrings is in the range

[ 51 , 129 , 138 , 141 ]. Microdisks and integrated microrings suffer from additional scattering losses at their top surface, which is usually rougher than their sidewall surface due to the pointed shape of the voxel tips.…”

Section: Devices Fabricated Via Tpp: General Applicationsmentioning

confidence: 99%

See 1 more Smart Citation

Two-Photon Polymerization: Functionalized Microstructures, Micro-Resonators, and Bio-Scaffolds

et al. 2021

The direct laser writing technique based on two-photon polymerization (TPP) has evolved considerably over the past two decades. Its remarkable characteristics, such as 3D capability, sub-diffraction resolution, material flexibility, and gentle processing conditions, have made it suitable for several applications in photonics and biosciences. In this review, we present an overview of the progress of TPP towards the fabrication of functionalized microstructures, whispering gallery mode (WGM) microresonators, and microenvironments for culturing microorganisms. We also describe the key physical-chemical fundamentals underlying the technique, the typical experimental setups, and the different materials employed for TPP.

Adv Materials Technologies

Optical Waveguides Fabricated via Femtosecond Direct Laser Writing: Processes, Materials, and Devices

Cao

Qiu

et al. 2023

As the most fundamental unit of photonic integration, optical waveguides offer the possibility of developing efficient and practical photonic chips by facilitating the on‐chip integration of devices with different functions. Femtosecond direct laser writing (FsDLW), as a burgeoning 3D microfabrication technology, can realize the rapid formation of arbitrary optical waveguides without any mask inside versatile materials, such as crystalline dielectric crystals, glasses, polymers, and photoresists. This significant material‐independence allows FsDLW to combine different materials and manufacturing processes to implement a cross‐platform solution. This review first describes the different optical loss types and suitable measurement methods for different applicable scenes, then summarizes the two fabrication mechanisms and points out the general direction for adjusting the waveguide properties by fabrication processes. Finally, the application fields and development prospects of different materials are discussed by overviewing the characteristics of different materials and the material selection preferences of different devices. With a panoramic view of the development, it is concluded with insights and perspectives of the future development of optical waveguides and processing technology via FsDLW.