Design of a novel optical sensor for the detection of waterborne bacteria based on a photonic crystal with an ultra-high sensitivity

2022 ◽  
Vol 54 (2) ◽  
Author(s):  
Malek G. Daher ◽  
Sofyan A. Taya ◽  
Ilhami Colak ◽  
Omar M. Ramahi
2015 ◽  
Vol 4 (1) ◽  
pp. 209-215 ◽  
Author(s):  
M. Mohebbi

Abstract. Silicon photonic crystal sensors have become very attractive for various optical sensing applications. Using silicon as a material platform provides the ability to fabricate sensors with other photonic devices on a single chip. In this paper, a new optical sensor based on optical resonance in a one-dimensional silicon photonic crystal with an air defect is theoretically studied for refractive index sensing in the infrared wavelength region. The air defect introduces a cavity into the photonic crystal, making it suitable for probing the properties of a gas found within the cavity. This photonic crystal nanocavity is designed to oscillate at a single mode with a high quality factor, allowing for refractive index sensing of gases with a high sensitivity. A method is presented to maximize the sensitivity of the sensor and to obtain a very narrow bandwidth cavity mode for good sensor resolution. We change the thickness of the air layers linearly in the photonic crystals on both sides of the nanocavity and show that a sensitivity of 1200 nm RIU−1 can be achieved. We present a detailed analysis of the sensor and variations of the layer thicknesses, the cavity length, and the number of periodic layers in the photonic crystal are investigated. This optical sensor has a much simpler design and higher sensitivity compared to other photonic crystal sensors reported previously.


Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Rostamian ◽  
Ehsan Madadi-Kandjani ◽  
Hamed Dalir ◽  
Volker J. Sorger ◽  
Ray T. Chen

Abstract Thanks to the unique molecular fingerprints in the mid-infrared spectral region, absorption spectroscopy in this regime has attracted widespread attention in recent years. Contrary to commercially available infrared spectrometers, which are limited by being bulky and cost-intensive, laboratory-on-chip infrared spectrometers can offer sensor advancements including raw sensing performance in addition to use such as enhanced portability. Several platforms have been proposed in the past for on-chip ethanol detection. However, selective sensing with high sensitivity at room temperature has remained a challenge. Here, we experimentally demonstrate an on-chip ethyl alcohol sensor based on a holey photonic crystal waveguide on silicon on insulator-based photonics sensing platform offering an enhanced photoabsorption thus improving sensitivity. This is achieved by designing and engineering an optical slow-light mode with a high group-index of n g  = 73 and a strong localization of modal power in analyte, enabled by the photonic crystal waveguide structure. This approach includes a codesign paradigm that uniquely features an increased effective path length traversed by the guided wave through the to-be-sensed gas analyte. This PIC-based lab-on-chip sensor is exemplary, spectrally designed to operate at the center wavelength of 3.4 μm to match the peak absorbance for ethanol. However, the slow-light enhancement concept is universal offering to cover a wide design-window and spectral ranges towards sensing a plurality of gas species. Using the holey photonic crystal waveguide, we demonstrate the capability of achieving parts per billion levels of gas detection precision. High sensitivity combined with tailorable spectral range along with a compact form-factor enables a new class of portable photonic sensor platforms when combined with integrated with quantum cascade laser and detectors.


2014 ◽  
Vol 105 (6) ◽  
pp. 063118 ◽  
Author(s):  
Daquan Yang ◽  
Shota Kita ◽  
Feng Liang ◽  
Cheng Wang ◽  
Huiping Tian ◽  
...  

2016 ◽  
Vol 25 (1) ◽  
pp. 25-31
Author(s):  
A. V. Egorov ◽  
N. L. Kazanskiy ◽  
P. G. Serafimovich

Photonics ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 40 ◽  
Author(s):  
Sohel Rana ◽  
Nirmala Kandadai ◽  
Harish Subbaraman

In this paper, a high sensitivity, polarization preserving photonic crystal fiber (PCF), based on circular air holes for sensing in the terahertz (THz) band, is presented. The finite element method, a practical and precise computational technique for describing the interactions between light and matter, is used to compute the modal properties of the designed fiber. For the designed PCF, comprising of circular air holes in both the cladding and in the porous core, a relative sensitivity of 73.5% and a high birefringence of 0.013 are achieved at 1.6 THz. The all circular air-hole structure, owing to its simplicity and compatibility with the current fiber draw technique for PCF fabrication, can be realized practically. It is anticipated that the designed fiber can be employed in applications such as detection of biological samples and toxic chemicals, imaging, and spectroscopy.


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