Slow Light Waveguide and Enhanced Area Microcavity Engineering for High Sensitivity Photonic Crystal Sensors

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.

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Unidirectional Slow Light Transmission in Heterostructure Photonic Crystal Waveguide

Applied Sciences ◽

10.3390/app8101858 ◽

2018 ◽

Vol 8 (10) ◽

pp. 1858 ◽

Cited By ~ 1

Author(s):

Qiuyue Zhang ◽

Xun Li

Keyword(s):

Photonic Crystal ◽

Slow Light ◽

Environmental Changes ◽

Light Transmission ◽

Square Lattice ◽

Manufacturing Defects ◽

Interfacial Defects ◽

Waveguide Design ◽

Light Waveguide ◽

Backward Propagation

In conventional photonic crystal systems, extrinsic scattering resulting from random manufacturing defects or environmental changes is a major source of loss that causes performance degradation, and the backscattering loss is amplified as the group velocity slows down. In order to overcome the limitations in slow light systems, we propose a backscattering-immune slow light waveguide design. The waveguide is based on an interface between a square lattice of magneto-optical photonic crystal with precisely tailored rod radii of the first two rows and a titled 45 degrees square lattice of Alumina photonic crystal with an aligned band gap. High group indices of 77, 68, 64, and 60 with the normalized frequency bandwidths of 0.444%, 0.481%, 0.485%, and 0.491% are obtained, respectively. The corresponding normalized delay-bandwidth products remain around 0.32 for all cases, which are higher than previously reported works based on rod radius adjustment. The robustness for the edge modes against different types of interfacial defects is observed for the lack of backward propagation modes at the same frequencies as the unidirectional edge modes. Furthermore, the transmission direction can be controlled by the sign of the externally applied magnetic field normal to the plane.

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Optimizing the slow light properties of slotted photonic crystal waveguide and its application in a high-sensitivity gas sensing system

Measurement Science and Technology ◽

10.1088/0957-0233/24/10/105109 ◽

2013 ◽

Vol 24 (10) ◽

pp. 105109 ◽

Cited By ~ 13

Author(s):

Ya-nan Zhang ◽

Yong Zhao ◽

Qi Wang

Keyword(s):

Photonic Crystal ◽

Slow Light ◽

Gas Sensing ◽

High Sensitivity ◽

Photonic Crystal Waveguide ◽

Sensing System

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Theoretical research on high sensitivity gas sensor due to slow light in slotted photonic crystal waveguide

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2012.07.051 ◽

2012 ◽

Vol 173 ◽

pp. 505-509 ◽

Cited By ~ 20

Author(s):

Ya-Nan Zhang ◽

Yong Zhao ◽

Di Wu ◽

Qi Wang

Keyword(s):

Photonic Crystal ◽

Gas Sensor ◽

Slow Light ◽

High Sensitivity ◽

Theoretical Research ◽

Photonic Crystal Waveguide

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Photonic crystal optical switch using a new slow light waveguide and heterostructure Y-junctions

Optik ◽

10.1016/j.ijleo.2013.05.006 ◽

2013 ◽

Vol 124 (23) ◽

pp. 6292-6297 ◽

Cited By ~ 6

Author(s):

Shahram Bahadori Haghighi ◽

Rahim Ghayour ◽

Babak Vakili

Keyword(s):

Photonic Crystal ◽

Slow Light ◽

Optical Switch ◽

Light Waveguide

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High sensitivity gas sensing method based on slow light in photonic crystal waveguide

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2012.04.056 ◽

2012 ◽

Vol 173 ◽

pp. 28-31 ◽

Cited By ~ 19

Author(s):

Yong Zhao ◽

Ya-nan Zhang ◽

Qi Wang

Keyword(s):

Photonic Crystal ◽

Slow Light ◽

Gas Sensing ◽

High Sensitivity ◽

Photonic Crystal Waveguide

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Dispersionless one-way slow wave with large delay bandwidth product at the edge of gyromagnetic photonic crystal

International Journal of Modern Physics B ◽

10.1142/s0217979220500861 ◽

2020 ◽

Vol 34 (10) ◽

pp. 2050086

Author(s):

Ye Liu ◽

Chun Jiang

Keyword(s):

Photonic Crystal ◽

Group Velocity ◽

Communication Systems ◽

Slow Light ◽

Weak Interactions ◽

Group Velocity Dispersion ◽

Edge State ◽

Group Index ◽

Light Waveguide ◽

Modal Field

We theoretically, demonstrate a high delay bandwidth product (DBP) and zero group velocity dispersion (GVD) in a two-dimensional one-way slow light waveguide. The waveguide consists of gyromagnetic photonic crystal (GMPC) and a cladding formed by silicon photonic crystal. At the edge of the band, weak interactions (“semi-anticrossing”) between the chiral edge state (CES) mode and the mode localized at the surface of cladding are observed. The group velocity of CES wave can be tuned by adjusting the modal field distribution. As a result, an extraordinarily large value of normalized DBP of 0.63 with a group index of 10.32 and a bandwidth ranging from [Formula: see text] to [Formula: see text] is obtained. This result may contribute to one-way slow light applications in information communication systems.

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