A Highly Sensitive, Polarization Maintaining Photonic Crystal Fiber Sensor Operating in the THz Regime

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.

Download Full-text

High sensitive triangular photonic crystal fiber sensor design applicable for gas detection

Advanced Electromagnetics ◽

10.7716/aem.v9i1.1539 ◽

2021 ◽

Vol 10 (1) ◽

pp. 1-5

Author(s):

A. Abbaszadeh ◽

S. Makouei ◽

S. Meshgini

Keyword(s):

Photonic Crystal ◽

Gas Sensor ◽

Photonic Crystal Fiber ◽

Relative Sensitivity ◽

Effective Area ◽

Industrial Applications ◽

Confinement Loss ◽

The Finite Element Method ◽

High Birefringence ◽

Crystal Fiber

A new triangular photonic crystal fiber with a based microstructure core gas sensor has been proposed for the wavelength range from 1.1μm to 1.7μm. The guiding trait of the proposed structure depends on geometric parameters and wavelength, which are numerically studied by the finite element method. According to the results, the relative sensitivity obtained as high as 75.14% at 1.33μm wavelength. high birefringence and effective area are also obtained by order of 3.75×10-3 and 14.07 μm2 finally, low confinement loss of 1.41×10-2 dB/m is acquired at the same wavelength. The variation of the diameters in the cladding and core region is investigated and the results show that this structure has good stability for manufacturing goals. Since the results show the highest sensitivity at wavelengths around 1.2μm to 1.7μm, which is the absorption line of many gases such as methane (CH4), hydrogen fluoride (HF), ammonia (NH3), this gas sensor can be used for medical and industrial applications.

Download Full-text

Design of Highly Sensitive Photonic Crystal Fiber for Sensing Harmful Chemicals

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.h6658.069820 ◽

2020 ◽

Vol 9 (8) ◽

pp. 804-809

Keyword(s):

Photonic Crystal ◽

Photonic Crystal Fiber ◽

High Sensitivity ◽

Relative Sensitivity ◽

Confinement Loss ◽

Crystal Fiber ◽

Wavelength Sensitivity ◽

Sensitivity Ratio ◽

Highly Sensitive ◽

Mode Area

Highly sensitive Photonic Crystal Fiber (PCF) has been designed and investigated for sensing the most harmful chemicals that exist in the world. The proposed structure of PCF consists of a solid circular core in which the samples of the chemicals are to be filled, surrounded by a hexagonal air-hole ring. The outermost cladding region comprises circular air-holes arranged in a helical (spiral) manner. Moreover, the sensitivity ratio of the liquid samples is investigated with respect to the wavelength. Sensitivity is monitored by checking for different wavelengths that range from 0.4µm to 1.85µm. With this proposed structure, the relative sensitivity of the chemicals such as paraffin liquid (n=1.48), pyridine (n=1.51), and bromobenzene (n=1.56) are found to be 78.49%, 82.99%, and 89.34% respectively. The proposed PCF structure is used to detect chemicals and any liquids due to its high sensitivity, large effective mode area, and low confinement loss

Download Full-text

A Highly Birefringent Photonic Crystal Fiber for Terahertz Spectroscopic Chemical Sensing

Sensors ◽

10.3390/s21051799 ◽

2021 ◽

Vol 21 (5) ◽

pp. 1799

Author(s):

Tianyu Yang ◽

Liang Zhang ◽

Yunjie Shi ◽

Shidi Liu ◽

Yuming Dong

Keyword(s):

Photonic Crystal ◽

Photonic Crystal Fiber ◽

Chemical Sensing ◽

Numerical Aperture ◽

Wide Band ◽

Relative Sensitivity ◽

Chemical Sensitivity ◽

High Birefringence ◽

Crystal Fiber ◽

Polarization Maintaining

A photonic crystal fiber (PCF) with high relative sensitivity was designed and investigated for the detection of chemical analytes in the terahertz (THz) regime. To ease the complexity, an extremely simple cladding employing four struts is adopted, which forms a rectangular shaped core area for filling with analytes. Results of enormous simulations indicate that a minimum 87.8% relative chemical sensitivity with low confinement and effective material absorption losses can be obtained for any kind of analyte, e.g., HCN (1.26), water (1.33), ethanol (1.35), KCN (1.41), or cocaine (1.50), whose refractive index falls in the range of 1.2 to 1.5. Besides, the PCF can also achieve high birefringence (∼0.01), low and flat dispersion, a large effective modal area, and a large numerical aperture within the investigated frequency range from 0.5 to 1.5 THz. We believe that the proposed PCF can be applied to chemical sensing of liquid and THz systems requiring wide-band polarization-maintaining transmission and low attenuation.

Download Full-text

Enhancement of relative sensitivity of photonic crystal fiber with high birefringence and low confinement loss

Optik ◽

10.1016/j.ijleo.2016.11.203 ◽

2017 ◽

Vol 131 ◽

pp. 697-704 ◽

Cited By ~ 14

Author(s):

Md. Faizul Huq Arif ◽

Md. Jaminul Haque Biddut

Keyword(s):

Photonic Crystal ◽

Photonic Crystal Fiber ◽

Relative Sensitivity ◽

Confinement Loss ◽

High Birefringence ◽

Crystal Fiber

Download Full-text

Proposal for a Quad-Elliptical Photonic Crystal Fiber for Terahertz Wave Guidance and Sensing Chemical Warfare Liquids

Photonics ◽

10.3390/photonics6030078 ◽

2019 ◽

Vol 6 (3) ◽

pp. 78 ◽

Cited By ~ 7

Author(s):

Izaddeen Yakasai ◽

Pg Emeroylariffion Abas ◽

Shubi F Kaijage ◽

Wahyu Caesarendra ◽

Feroza Begum

Keyword(s):

Photonic Crystal ◽

Photonic Crystal Fiber ◽

Fractional Power ◽

Relative Sensitivity ◽

Chemical Warfare ◽

Confinement Loss ◽

Thz Radiation ◽

High Birefringence ◽

Crystal Fiber ◽

Power Fraction

A porous-core photonic crystal fiber based on a cyclic olefin homopolymer (Zeonex) is proposed; it shows high birefringence, high core power fraction, low losses, and near-zero flat dispersion. The fiber’s core was designed with quad-elliptical (QE) air holes with its center occupied by bulk background material. The superiority of the QE design over the commonly adopted tri- and penta-elliptical (TE and PE) core designs is demonstrated. The presence of the bulk material at the core center and the geometrical configuration cause a broad contrast in phase refractive indices, thereby producing high birefringence and low transmission losses. A high birefringence of 0.096 was obtained at 1.2 THz, corresponding to a total loss of 0.027 cm−1 and core power fraction of approximately 51%. The chromatic dispersion and effective area of the reported fiber were also characterized within a frequency range of 0.4–1.6 THz. The QE air holes were then filled with chemical warfare agents, namely, tabun and sarin liquids. Then, the relative sensitivity, confinement loss, fractional power flow, and effective material loss (EML) of the sensor were calculated. Nearly the same relative sensitivity (r = 64%) was obtained when the QE core was filled with either liquid. Although the obtained EML for tabun was 0.033 cm−1 and that for sarin was 0.028 cm−1, the confinement loss of the fiber when it was immersed in either liquid was negligible. The proposed fiber can be fabricated using existing fabrication technologies. Moreover, it can be applied and utilized as a THz radiation conveyor in a terahertz time domain spectroscopy system for remote sensing of chemical liquids in the security and defense industries.

Download Full-text