الفهرس 
FundamentalsOnly 14 pages are availabe for public view
 |  | from | 90 |  |  |
| | | from | 90 | | |
Abstract
The main objective of this thesis is to introduce and develop new efficient biosensors by using one-dimensional photonic crystal. The transmission spectrum is calculated numerically by using the transfer matrix method (TMM).
In Chapter 1, we give a general introduction to the history of biosensors. We also clarify the structure of sensors. Then, we show the principle of photonic biosensor.
In Chapter 2, we propose a defective one-dimensional photonic crystal (1D-PC) based on Si/SiO2-layers with a central liquid defect layer as a blood sugar concentration biosensor in the visible region. The thickness of the defect layer and incident angle are optimized to achieve the best performance of the sensor. The results show that the localization of defect mode shifts to a longer wavelength with increasing the defect layer thickness. In addition to increasing the incident angle from θ0 = 00 to θ0 = 900, the defect peak was shifted towards the short wavelength region. The optimized value of our structure demonstrates high sensitivity for the blood sugar (S = 1100nm/RIU) in the range of concentration 0 to 500 mg/dl, more enhancement of the quality factor (3.539×106) and a very low limit of detection (8.8×10-9RIU) are achieved. Our results indicate that the proposed structure has higher performance as a blood sugar sensor than many previously reported data. Besides, the simplicity of the proposed structure makes it favorable to the industrial design using inexpensive and massive product nanofabrication techniques.
In Chapter 3, we develop an optical Gas sensor that is very important in many fields such as for environmental monitoring, agricultural production, public safety, and medical diagnostics.
Herein, Tamm plasmon resonance in one-dimensional porous is used as an optical gas sensor with high performance. The structure of the proposed sensor is consisting of gas cavity sandwich between one-dimensional porous silicon photonic crystals covered and Ag layer. The optimized structure of the proposed sensor achieved ultra-high sensitivity (S = 1.9 × 105nm/RIU) compared to many previous gas sensors. The brilliant sensing performance and the simple design of the proposed structure makes it highly suitable for use as a sensor in different industrial and medical sectors.
In Chapter 4, In Chapter 4, we study the effect of temperature on the performance of the proposed sensor in the previous chapter.
Finally in Chapter 5, We used the structure that mentioned in chapter 2 to develop a model for a high sensitivity cancer cells sensor using a one-dimensional photonic crystal. The defect layer thickness, and incident angle of the electromagnetic wave were optimised to achieve high performance of the biosensor. The proposed sensor has S = 1 × 103nm/RIU, FOM = 10 × 103(/RIU), Q - factor = 8 × 103, and DL = 5 × 10-6RIU.
All the computations in this thesis are carried out using MATLAB version 2019 on a laptop with the configuration: Intel(R) Core (TM) i5 CPU, 8.00G RAM and 2.67GHz, with 64 bits operation system.