CN116337815A - Nested micro-ring refractive index sensing device based on SWG waveguide and vernier effect - Google Patents
Nested micro-ring refractive index sensing device based on SWG waveguide and vernier effect Download PDFInfo
- Publication number
- CN116337815A CN116337815A CN202310304972.9A CN202310304972A CN116337815A CN 116337815 A CN116337815 A CN 116337815A CN 202310304972 A CN202310304972 A CN 202310304972A CN 116337815 A CN116337815 A CN 116337815A
- Authority
- CN
- China
- Prior art keywords
- ring
- waveguide
- micro
- silicon
- refractive index
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000000694 effects Effects 0.000 title claims abstract description 17
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 28
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 23
- 239000010703 silicon Substances 0.000 claims abstract description 23
- 239000000758 substrate Substances 0.000 claims abstract description 12
- 238000005253 cladding Methods 0.000 claims abstract description 9
- 230000003287 optical effect Effects 0.000 claims abstract description 8
- 238000000034 method Methods 0.000 claims abstract description 5
- 239000012491 analyte Substances 0.000 claims abstract description 4
- 230000003993 interaction Effects 0.000 claims abstract description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 10
- 230000008878 coupling Effects 0.000 claims description 9
- 238000010168 coupling process Methods 0.000 claims description 9
- 238000005859 coupling reaction Methods 0.000 claims description 9
- 239000000377 silicon dioxide Substances 0.000 claims description 5
- 238000005452 bending Methods 0.000 claims description 4
- 235000012239 silicon dioxide Nutrition 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims 1
- 230000035945 sensitivity Effects 0.000 abstract description 9
- 230000003595 spectral effect Effects 0.000 abstract description 4
- 230000007613 environmental effect Effects 0.000 abstract description 2
- 238000012544 monitoring process Methods 0.000 abstract description 2
- 238000005259 measurement Methods 0.000 abstract 1
- 238000001514 detection method Methods 0.000 description 3
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 238000000411 transmission spectrum Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000002210 silicon-based material Substances 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
- G01N21/45—Refractivity; Phase-affecting properties, e.g. optical path length using interferometric methods; using Schlieren methods
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
- G01N21/45—Refractivity; Phase-affecting properties, e.g. optical path length using interferometric methods; using Schlieren methods
- G01N2021/458—Refractivity; Phase-affecting properties, e.g. optical path length using interferometric methods; using Schlieren methods using interferential sensor, e.g. sensor fibre, possibly on optical waveguide
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention provides a nested micro-ring refractive index sensing device based on SWG waveguide and vernier effect. The method is characterized in that: the micro-ring waveguide consists of an SOI substrate 1, a micro-ring 2 formed by trapezoid silicon columns with subwavelength periodicity, a U-shaped nested ring waveguide 3 formed by rectangular silicon columns with subwavelength periodicity, a silicon ring 4 and an object to be measured cladding 5. The sub-wavelength grating waveguide enhances the interaction region of the optical field with the analyte, thereby increasing the sensitivity of the sensing device. The structure is based on a traditional Add-Drop micro-ring resonator, a Through port is connected with an Add port to form a U-shaped waveguide, and an optical signal passing Through the Through port generates phase change and is reloaded to the Add port to interfere with an optical signal of an original Drop port. The free spectral range of the U-shaped nested micro-ring is increased to twice the original free spectral range. Because the traditional sensing measurement offset is smaller, the vernier effect is utilized by the existence of the reference ring in the structure, so that the wavelength offset is multiplied. The invention can be used in the fields of environmental monitoring and biosensing.
Description
Technical Field
The invention designs a nested micro-ring refractive index sensing device based on SWG waveguide and vernier effect, which can be used in the fields of environmental monitoring and biosensing.
Background
In recent years, many optical fiber sensors based on fiber bragg gratings, long period gratings, etc. have been widely studied, and these sensors are suitable for distributed strain sensing or temperature sensing, but the optical fiber sensors are bulky for biosensing and refractive index sensing. A miniaturized integrated silicon-based sensing structure is therefore proposed. The optical sensor based on the micro-ring resonator structure is focused by researchers, and the introduction of the resonance effect enables the optical signal to continuously circulate in the resonant cavity, which is equivalent to the increase of the sensing length, and the optical sensor can realize excellent sensing performance and has the advantage of small size. Most of the micro-ring structures are based on the interaction between evanescent waves and biomolecules adsorbed or immobilized on the sensor surface, and the sensitivity of the micro-ring structures decreases when the thickness of the analyte accumulated on the sensor surface increases, so as to improve the problems, a sub-wavelength grating waveguide is proposed. A sub-wavelength grating is a grating whose grating period is much smaller than the wavelength of the incident light, and is typically characterized by its mode exhibiting delocalization. Unlike conventional silicon waveguides, which confine light in a waveguide, energy is primarily distributed at the outer edge when light is transmitted in a sub-wavelength grating waveguide. The contact area between the light and the object to be detected is effectively increased, the surface sensing capability of the device is improved, and finally the sensitivity is improved.
The invention provides a nested micro-ring refractive index sensing device based on SWG waveguide and vernier effect, the sensitivity of the sensing device can be improved by introducing a sub-wavelength grating structure, and as the binding capacity of the sub-wavelength grating structure to light is weaker than that of the traditional waveguide, the bending loss of the sub-wavelength grating structure can be increased, the working performance of the sensor is affected, and in order to realize the compactness of the device and the reduction of the bending loss, a trapezoid structure is used for replacing a rectangular structure; the U-shaped nested micro-ring structure can increase the Free Spectral Range (FSR) by 1 time compared with the traditional Add-Drop micro-ring; the introduction of the reference ring can provide stable comb spectrum for the sensing ring by utilizing vernier effect, so that wavelength shift is multiplied.
Disclosure of Invention
The invention designs a nested micro-ring refractive index sensing device based on SWG waveguide and vernier effect, and obtains large FSR and high sensitivity. In deionized water environment, sensitivity near 1550nm reaches 353.37nm/RIU, and detection limit LOD is 5.659 ×10 -5 RIU。
The purpose of the invention is realized in the following way:
the micro-ring structure consists of an SO1 substrate 1, a micro-ring 2 formed by trapezoid silicon columns with subwavelength periodicity, a U-shaped nested ring waveguide 3 of a rectangular silicon column with subwavelength periodicity, a silicon ring 4 and an object cladding 5 to be measured.
Preferably, the SOI substrate has a thickness d sio2 Width w sio2 Length of l sio2 。
Preferably, the bottom side a of the trapezoid silicon pillar si Top edge b si Width w si Thickness d si The micro-ring radius is R 1 。
Preferably, the rectangular silicon pillars have a period P and a width w si Duty ratio f, thickness d si U-ring one-sided coupling length L c The radius of the U-shaped ring is R 2 。
Preferably, the width w of the ring silicon ring is referenced si Thickness d si Radius of R 3 The thickness of the object to be measured is d a 。
Preferably, the SOI substrate has a refractive index n sio2 Silicon dioxide of =1.44, silicon refractive index in silicon waveguide n si ＝3.47。
Drawings
FIG. 1 is a front view of the structure of a nested micro-ring refractive index sensing device based on SWG waveguides and vernier effects.
FIG. 2 is a top view of a three-dimensional structure of a nested micro-ring refractive index sensing device based on SWG waveguides and vernier effects.
FIG. 3 is a three-dimensional structural detail of a nested micro-ring refractive index sensing device based on SWG waveguides and vernier effects.
FIG. 4 is a graph of the transmission spectrum of a sensor designed.
Fig. 5 is the sensitivity at a sub-wavelength grating duty cycle f=0.7.
The sensor designed in FIG. 6 has a gap in the coupling gap 1 Frequency shift plot of formants with cladding refractive index for a duty cycle of f=0.7.
Detailed Description
The invention is further illustrated below in conjunction with specific examples.
As shown in fig. 1, 2 and 3, the invention provides a refractive index sensing device of a U-shaped nested micro-ring resonator based on a sub-wavelength grating and vernier effect. The device consists of a multi-layer structure, an SOI substrate (1), a micro-ring (2) formed by trapezoid silicon columns with sub-wavelength periodicity, a U-shaped waveguide (3) with rectangular silicon columns with sub-wavelength periodicity, a silicon ring (4) and an object cladding (5) to be measured.
As an example, the sensor has a structure in which the width w of the SOI substrate is as follows sio2 The SOI substrate has a length of l sio2 Thickness d sio2 The bottom edge length of the trapezoid structure of the sub-wavelength grating forming the micro-ring is a si Length of top edge b si Width w si Thickness d si Microring radius R 1 =3um; the width of the sub-wavelength grating rectangular structure forming the straight waveguide is w si Length l si Thickness d si The radius of the U-shaped nested structure is R 2 The coupling length is Lc, the coupling gap is gap 1 The method comprises the steps of carrying out a first treatment on the surface of the The radius of the reference ring is r3, and the coupling gap is gap 2 . The SOI substrate has a refractive index n sio2 Silicon dioxide material=1.44, silicon waveguide adopts refractive index n si Silicon material=3.47.
Performance parameters for a micro-ring resonant sensor. The Free Spectral Range (FSR) represents the separation of the resonant wavelengths of two adjacent resonant orders when the microring radius is unchanged, as defined by the formula
Calculated, where lambda is the wavelength, n eff The effective refractive index, m is the resonant order; the quality factor Q represents the number of resonances used to dissipate the light energy circulating in the micro-ring to an initial value of 1/e, expressed by the formula +.>
Calculating to obtain; the sensitivity reflects the advantages and disadvantages of the sensing performance of the sensing device, which is defined by->
The detection limit is obtained by +.>
And (5) calculating to obtain the product.
The transmission spectrum of this example is shown in fig. 3 when the cladding is deionized water, and the simulation result is calculated by CST Microwave Studio 2019 software. Determining the coupling gap, period, duty cycle of sub-wavelength grating and radius of reference ring by parameter scanning to obtain sensitivity reaching 353.37nm/RIU near 1550nm, corresponding detection Limit (LOD) of 5.659 ×10 -5 RIU。
Claims (3)
1. Nested micro-ring refractive index sensing device based on SWG waveguide and vernier effect; the method is characterized in that: the device consists of an SOI substrate 1, a micro-ring 2 formed by trapezoid silicon columns with subwavelength periodicity, a U-shaped waveguide 3 formed by rectangular silicon columns with subwavelength periodicity, a silicon ring 4 and an object cladding 5 to be measured; the width of the SOI substrate in the system is
Length of->
Thickness of->
The silicon heights in the structure are d si The width of the rectangular silicon strip is w si Length l si The bottom edge of the trapezoid silicon strip is a si The top edge is b si Width w si The period of the sub-wavelength grating is p, the duty ratio is f, and the micro-ring radius is R 1 The radius of the reference ring is R 2 The radius of the U-shaped waveguide is R 3 The coupling gap between the sub-wavelength grating micro-ring and the straight waveguide is gap 1 The coupling gap between the reference ring and the straight waveguide is gap 2 Single side coupling distance L c 。
2. The nested micro-ring refractive index sensing device based on SWG waveguides and vernier effects of claim 1, characterized by: the whole structure is respectively an SOI substrate, a silicon waveguide and a cladding of an object to be measured from bottom to top; the SOI substrate is composed of silicon dioxide, the sub-wavelength grating waveguide is composed of silicon, and the top layer covers the cladding of the object to be detected; wherein the thickness of the silicon dioxide is
Thickness of silicon d si The cladding thickness of the object to be measured is selected as d a The method comprises the steps of carrying out a first treatment on the surface of the Refractive index of silica>
Refractive index n of silicon si 。
3. The nested microring refractive index sensing device based on SWG waveguides and vernier effects of claim 1; the method is characterized in that: the constraint capacity of the sub-wavelength grating waveguide for the optical field is lower than that of the traditional bar waveguide, a large number of mode fields are positioned in an air gap with low refractive index, the interaction volume between light and an analyte is enhanced, and the analyte between silicon block structures introduces high field intensity to further enhance the interaction between the light and a substance; however, in the micro-ring structure with the same size, the bending loss of the sub-wavelength grating waveguide is obviously higher than that of the traditional strip waveguide, and in order to achieve the coexistence of compact structure and high Q, the trapezoid structure is used to achieve smaller bending loss on the basis of small size; based on an Add-Drop micro-ring resonator, providing a U-shaped waveguide with the length equal to the circumference of the micro-ring, and connecting a Through port with the Add port; the reference ring is selected by multiplying the wavelength shift by vernier effect; in practical sensing application, light meeting the resonance wavelength of the reference ring in the optical signal passing through the Input port is coupled into the reference ring, light meeting the resonance wavelength of the sensing ring is coupled into the sensing ring after passing through the straight waveguide, light with the non-resonance wavelength enters the U-shaped waveguide, the light passing through the U-shaped waveguide is reloaded to the Add port, and the light at the place interferes with the light at the original Drop port.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310304972.9A CN116337815A (en) | 2023-03-27 | 2023-03-27 | Nested micro-ring refractive index sensing device based on SWG waveguide and vernier effect |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310304972.9A CN116337815A (en) | 2023-03-27 | 2023-03-27 | Nested micro-ring refractive index sensing device based on SWG waveguide and vernier effect |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116337815A true CN116337815A (en) | 2023-06-27 |
Family
ID=86880188
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310304972.9A Pending CN116337815A (en) | 2023-03-27 | 2023-03-27 | Nested micro-ring refractive index sensing device based on SWG waveguide and vernier effect |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116337815A (en) |
-
2023
- 2023-03-27 CN CN202310304972.9A patent/CN116337815A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Jin et al. | Highly-sensitive silicon-on-insulator sensor based on two cascaded micro-ring resonators with vernier effect | |
| Subramanian et al. | Silicon and silicon nitride photonic circuits for spectroscopic sensing on-a-chip | |
| Zhao et al. | Compact SOI optimized slot microring coupled phase-shifted Bragg grating resonator for sensing | |
| US9052291B2 (en) | Optical sensor based on a broadband light source and cascaded waveguide filters | |
| US7184135B2 (en) | Refractometer with blazed bragg gratings | |
| WO2014198409A1 (en) | Integrated optical waveguide sensor system | |
| US20130094029A1 (en) | Vernier photonic sensor data-analysis | |
| US9671335B2 (en) | Photonics integrated interferometric system and method | |
| Høvik et al. | Waveguide asymmetric long-period grating couplers as refractive index sensors | |
| Ohtera et al. | Photonic crystals for the application to spectrometers and wavelength filters | |
| CN116337815A (en) | Nested micro-ring refractive index sensing device based on SWG waveguide and vernier effect | |
| Sahu et al. | Modeling of grating slot waveguide for high-Q based refractive index sensor | |
| Huang et al. | Dual-parameter optical sensor with cascaded ring resonators for simultaneous refractive index and temperature sensing | |
| CN113916839B (en) | Seawater temperature and salt sensor based on double guided mode resonance effect, and measuring system and method | |
| CN110873701B (en) | Optical fiber humidity sensor based on Mach-Zehnder interferometer | |
| CN113514420B (en) | High-sensitivity sensor with double U-shaped waveguide structure | |
| WO2002044697A1 (en) | Refractometer with blazed bragg gratings | |
| Rasras et al. | Lab-on-Chip Silicon Photonic Sensor | |
| Igarashi et al. | Si-microring resonator with sidewall nanograting structures for high-Q resonance modes | |
| Wang et al. | Simulation of Refractive Index Sensor Based on Microring Resonator | |
| Liao et al. | Investigation of a Subwavelength Grating Bimodal Interferometric Sensor Built on Silicon Nitride Platform | |
| KR102206850B1 (en) | Ring resonator sensor based on multimode waveguide | |
| KR101130686B1 (en) | Hydrogen sensor, Production method of it and The hydrogen consistency measuring equipment which uses it | |
| Heinsalu et al. | Design and record-high experimental demonstration of compact and high-sensitive SW-MS BG refractive index sensor on SOI platform | |
| El Shamy et al. | Compact Gas Sensor Using Silicon-on-Insulator Loop-Terminated Mach–Zehnder Interferometer. Photonics 2022, 9, 8 |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication |