Self-referencing waveguide grating sensors
First Claim
1. An athermal self-referencing optical sensor comprising:
- a substrate;
a lower waveguide grating structure;
a buffer layer; and
an upper waveguide grating structure, wherein said lower waveguide grating structure has a thickness that was sized to make a rate of change of a lower resonant wavelength/temperature variation (Δ
λ
L/Δ
T) of said lower waveguide grating structure substantially equal to a rate of change of an upper resonant wavelength/temperature variation (Δ
λ
U/Δ
T) of said upper waveguide grating structure.
1 Assignment
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Accused Products
Abstract
Self-referencing optical sensors and methods are described herein that can be used to detect bio-chemical interactions (e.g., biological binding of antigen-antibody pairs) that occur in for example a microplate. In one embodiment, the self-referencing optical sensor includes a substrate, a lower (reference) waveguide grating structure, a buffer layer and an upper (sensing) waveguide grating structure. This self-referencing optical sensor enables an optical interrogation system to detect a bio-chemical interaction independent of the effect of temperature by measuring a reference signal associated with the lower (reference) waveguide grating structure and measuring a sensing signal associated with the upper (sensing) waveguide grating structure. These two signals are then subtracted from one another to determine a sensing measurement that represents whether or not the bio-chemical interaction occurred that is independent of the effect of temperature. This is all possible because the self-referencing optical sensor has a lower (reference) waveguide grating structure with a thickness that was sized to make a rate of change of a lower resonant wavelength/temperature variation (ΔλL/ΔT) substantially equal to a rate of change of an upper resonant wavelength/temperature variation (ΔλU/ΔT). Several other embodiments of self-referencing optical sensors which have a specific structures and/or a specific compositions are also described herein.
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Citations
32 Claims
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1. An athermal self-referencing optical sensor comprising:
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a substrate;
a lower waveguide grating structure;
a buffer layer; and
an upper waveguide grating structure, wherein said lower waveguide grating structure has a thickness that was sized to make a rate of change of a lower resonant wavelength/temperature variation (Δ
λ
L/Δ
T) of said lower waveguide grating structure substantially equal to a rate of change of an upper resonant wavelength/temperature variation (Δ
λ
U/Δ
T) of said upper waveguide grating structure. - View Dependent Claims (2, 3)
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4. A method for detecting a biochemical interaction in a sensing region of an optical sensor, said method comprising the steps of:
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directing a light beam at the optical sensor which includes;
a substrate;
a lower waveguide grating structure;
a buffer layer; and
an upper waveguide grating structure, wherein said lower waveguide grating structure has a thickness that was sized to make a rate of change of a lower resonant wavelength/temperature variation (Δ
λ
L/Δ
T) of said lower waveguide grating structure substantially equal to a rate of change of an upper resonant wavelength/temperature variation (Δ
λ
U/Δ
T) of said upper waveguide grating structure;
receiving an output optical beam from said optical sensor; and
analyzing the output optical beam to determine a reference signal and a sensing signal which are then subtracted from one another to determine a self-referenced sensing measurement which indicates whether or not the bio-chemical interaction took place in the sensing region of said optical sensor. - View Dependent Claims (5)
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6. An athermal self-referencing optical sensor comprising:
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a substrate;
an anti-resonant reflecting optical waveguide (ARROW) grating structure;
a buffer layer; and
an upper waveguide grating structure. - View Dependent Claims (7, 8, 9)
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10. A method for detecting a bio-chemical interaction in a sensing region of an optical sensor, said method comprising the steps of:
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directing a light beam at the optical sensor which includes;
a substrate;
an anti-resonant reflecting optical waveguide (ARROW) grating structure;
a buffer layer; and
an upper waveguide grating structure;
receiving an output optical beam from said optical sensor; and
analyzing the output optical beam to determine a reference signal and a sensing signal which are then subtracted from one another to determine a self-referenced sensing measurement which indicates whether or not the bio-chemical interaction took place in a sensing region of said optical sensor. - View Dependent Claims (11, 12)
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13. An athermal self-referencing optical sensor comprising:
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a substrate;
a Bragg waveguide grating structure;
a buffer layer; and
an upper waveguide grating structure. - View Dependent Claims (14, 15)
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16. A method for detecting a bio-chemical interaction in a sensing region of an optical sensor, said method comprising the steps of:
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directing a light beam at the optical sensor which includes;
a substrate;
a Bragg waveguide grating structure;
a buffer layer; and
an upper waveguide grating structure;
receiving an output optical beam from said optical sensor; and
analyzing the output optical beam to determine a reference signal and a sensing signal which are then subtracted from one another to determine a self-referenced sensing measurement which indicates whether or not the bio-chemical interaction took place in the sensing region of said optical sensor. - View Dependent Claims (17, 18)
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19. An optical sensor comprising:
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a substrate; and
a waveguide grating structure, wherein when said waveguide grating structure is interrogated then one can use higher mode properties of said waveguide grating structure to separate effects of a surface binding thickness (Δ
tbio) from changes in a buffer solution refractive index (Δ
nanalyte). - View Dependent Claims (20)
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21. A method for detecting a bio-chemical interaction in a sensing region of an optical sensor, said method comprising the steps of:
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directing a light beam at the optical sensor which includes;
a substrate; and
a waveguide grating structure;
receiving an output optical beam from said optical sensor; and
analyzing said received optical beam and using higher mode properties of said waveguide grating structure to separate effects of a surface binding thickness (Δ
tbio) from changes in a buffer solution refractive index (Δ
nanaylyte) to determine whether or not the bio-chemical interaction took place in the sensing region of said optical sensor. - View Dependent Claims (22)
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23. An optical sensor comprising:
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a substrate;
a reference waveguide grating structure;
a barrier layer; and
a sensing waveguide grating structure, wherein a thickness and a refractive index of said barrier layer were determined so there is a high isolation for a quasi-guided mode of said reference waveguide grating structure and so that the quasi-guided mode is biased towards a sensing region of said sensing waveguide grating structure. - View Dependent Claims (24, 25)
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26. A method for detecting a bio-chemical interaction in a sensing region of an optical sensor, said method comprising the steps of:
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directing a light beam at the optical sensor which includes;
a substrate;
a reference waveguide grating structure;
a barrier layer; and
a sensing waveguide grating structure, wherein a thickness and a refractive index of said barrier layer were determined so there is a high isolation for a quasi-guided mode of said reference waveguide grating structure and so that the quasi-guided mode is biased towards a sensing region of said sensing waveguide grating structure;
receiving an output optical beam from said optical sensor; and
analyzing the output optical beam to determine a reference signal and a sensing signal which are then subtracted from one another to determine a self-referenced sensing measurement which indicates whether or not the bio-chemical interaction took place in the sensing region of said optical sensor. - View Dependent Claims (27)
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28. The optical sensor comprising:
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a substrate;
a lower waveguide grating structure;
a buffer layer; and
an upper waveguide grating structure, wherein said lower waveguide grating structure has a waveguide mode that is operated in TM polarization and said upper waveguide grating structure has a waveguide mode that is operated in TE polarization. - View Dependent Claims (29, 30)
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31. A method for detecting a biochemical interaction in a sensing region of an optical sensor, said method comprising the steps of:
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directing a light beam at the optical sensor which includes;
a substrate;
a lower waveguide grating structure;
a buffer layer; and
an upper waveguide grating structure, wherein said lower waveguide grating structure has a waveguide mode that is operated in TM polarization and said upper waveguide grating structure has a waveguide mode that is operated in TE polarization;
receiving an output optical beam from said optical sensor; and
analyzing the output optical beam to determine a reference signal and a sensing signal which are then subtracted from one another to determine a self-referenced sensing measurement which indicates whether or not the bio-chemical interaction took place in a sensing region of said optical sensor. - View Dependent Claims (32)
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Specification