Integrated label-free optical biochemical sensor with a large measurement range based on an angular grating-microring resonator

Abstract

We propose and design a photonic-integrated optical biochemical sensor, which comprises a microring resonator and angular gratings in a silicon-on-insulator waveguide. With the combination of the angular gratings, the measurement range of the angular grating-microring resonator-based sensor significantly increases without the restriction of a free spectral range. Optimization of the several key structural parameters is investigated to achieve favorable transmission properties. A high-quality factor of more than 1.03×10⁵ can meet the requirements of high sensitivity and low detection limit. The simulation results on the biochemical bulk sensing show that a concentration sensitivity of more than 95.27 pm/% and detection limit of less than 0.329% can be obtained. A large measurement range of 50.2 nm is achieved by the combination of the angular gratings. The investigation on the combination of microring resonator and angular grating is a valuable exploration of the liquid and gas biomedical sensing for the ultra-large measurement range.

Compact Inner-Wall Grating Slot Microring Resonator for Label-Free Sensing

“…As concluded in Table 2, the concentration sensitivities of the sensor for sodium chloride solutions and D-glucose solutions are 996.91 pm/% and 968.05 pm/%, respectively. Compared with [19], both solution concentrations are over 10 times that of 95.27 pm/% and 95.33 pm/%, respectively. The RP2 for linear fit is less than the RP2 for parabolic fit, which illustrates that the 2 order parabolic fitting can depict the function relationship between the resonance wavelength and solution concentration more precisely than linear fitting [19,28,29,30,31].…”

“…However, the detection range of conventional MRR sensor based on the wavelength shift is severely constrained by the small free spectral region (FSR). In order to enlarge the detection range, some schemes, such as serially coupled double MRRs [15], the MRR with bent contra-directional couplers [16], Mach–Zehnder interferential couple MRR [17], grating-coupled silicon MRR [18], and angular grating MRR [19] are investigated to expand the FSR. These schemes can enlarge the FSR, but the sensitivities of the above schemes are relativity lower than the sensitivity of SMRR.…”

Compact Inner-Wall Grating Slot Microring Resonator for Label-Free Sensing

“…Table 2, the concentration sensitivities of the sensor for sodium chloride solutions and D-glucose solutions are 960.61 pm/% and 933.06 pm/%, respectively. Compared with[19], both solution concentrations are about 10 times than that of 95.27 pm/% and 95.33 pm/%, respectively. The R 2 P for linear fit is less than the R 2 P for parabolic fit, which illustrates that the 2 order parabolic fitting can depict the function relationship between the resonance wavelength and solution concentration more precisely than linear fitting[19,27,[28][29][30].…”

“…Compared with[19], both solution concentrations are about 10 times than that of 95.27 pm/% and 95.33 pm/%, respectively. The R 2 P for linear fit is less than the R 2 P for parabolic fit, which illustrates that the 2 order parabolic fitting can depict the function relationship between the resonance wavelength and solution concentration more precisely than linear fitting[19,27,[28][29][30]. For the low concentration variations of sodium chloride solutions, R 2 P for linear fit is 0.99992, which shows the relationship between the resonance wavelength and solution concentration is nearly linear.…”

“…However, the detection range of MRR sensor based on the wavelength shift-dependent is severely constrained by the small FSR. In order to enlarge the detection range, some schemes, such as serially coupled double MRRs [15], the MRR with bent contra-directional couplers [16], Mach-Zehnder interferential couple MRR [17], grating-coupled silicon MRR [18] and angular grating MRR [19] are investigated to expand the FSR. These schemes can enlarge the FSR, but the sensitivities of the above schemes are relativity lower than the sensitivity of SMRR.…”