| 1. |
- Beal, Jacob, et al.
(author)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
Journal article (peer-reviewed)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
|
|
| 2. |
- Li, Xiaohui, et al.
(author)
-
Concentric silicon micro-ring resonators with enhanced transmission notch depth
- 2008
-
In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE.
-
Conference paper (peer-reviewed)abstract
- In this work, we have analyzed, fabricated and demonstrated concentric micro-ring resonators in silicon-on-insulator (SOI) structure for enhanced transmission notches. The operation principles of the concentric ring resonators are studied by time-domain coupled-mode theory. Directional coupling between concentric rings offers another freedom in designing deep notch optical filters and ultra-sensitive biosensors. The finite-difference-time-domain (FDTD) simulations have shown the improvement of the notch depth, evenly distributed mode field and the effect of the resonance shift. The device is demonstrated in silicon-on-insulator structure. Transmission notch depth improvement of ~ 15dB is demonstrated for the 21-20.02-μm-radius double-ring structure comparing with the single 21-μm-radius ring.
|
|
| 3. |
- Su, Y., et al.
(author)
-
Signal processing in silicon waveguides
- 2009
-
In: 2009 Asia Communications and Photonics Conference and Exhibition, ACP 2009. - Washington, D.C. : OSA. - 9781557528773 ; , s. 5377017-
-
Conference paper (peer-reviewed)abstract
- We experimentally demonstrate optical signal processing in silicon ring resonators, including slow and fast in silicon rings, optical delay of digital and microwave photonic signals, dense wavelength conversions/multicasting, optical up-conversion, format conversions, temporal differentiation, and bio-sensing.
|
|
| 4. |
- Chang, Qingjiang, et al.
(author)
-
A Tunable Broadband Photonic RF Phase Shifter Based on a Silicon Microring Resonator
- 2009
-
In: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1041-1135 .- 1941-0174. ; 21:1-4, s. 60-62
-
Journal article (peer-reviewed)abstract
- We propose and demonstrate a tunable broadband photonic radio frequency (RF) phase shifter based on a silicon microring resonator. This scheme utilizes the thermal nonlinear effect of the silicon microring to change the electrical phase of the RF signal with a wide tuning range. A prototype of the phase shifter is experimentally demonstrated for a 40-GHz signal with a 0-4.6-rad tuning range.
|
|
| 5. |
|
|
| 6. |
- Cui, Jinxing, et al.
(author)
-
Structural Deformation of Sm@C88under High Pressure
- 2015
-
In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 5
-
Journal article (peer-reviewed)abstract
- We have studied the structural transformation of Sm@C88 under pressure up to 18 GPa by infraredspectroscopy combined with theoretical simulations. The infrared-active vibrational modes of Sm@C88 at ambient conditions have been assigned for the first time. Pressure-induced blue and red shiftsof the corresponding vibrational modes indicate an anisotropic deformation of the carbon cage uponcompression. We propose that the carbon cage changes from ellipsoidal to approximately sphericalaround 7 GPa. A smaller deformation of the carbon bonds in the area close to the Sm atom in thecage suggests that the trapped Sm atom plays a role in minimizing the compression of the adjacentbonds. Pressure induced a significant reduction of the band gap of the crystal. The HOMO-LUMOgap of the Sm@C88 molecule decreases remarkably at 7 GPa as the carbon cage is deformed. Also,compression enhances intermolecular interactions and causes a widening of the energy bands. Botheffects decrease the band gap of the sample. The carbon cage deforms significantly above 7 GPa,from spherical to a peanut-like shape and collapses at 18 GPa.
|
|
| 7. |
- Li, Qiang, et al.
(author)
-
All-optical NRZ-to-AMI conversion using linear filtering effect of silicon microring resonator
- 2009
-
In: Chinese optics letters. - : Shanghai Institute of Optics and Fine Mechanics. - 1671-7694. ; 7:1, s. 12-14
-
Journal article (peer-reviewed)abstract
- We experimentally demonstrate 10-Cb/s format conversion from non-return-to-zero (NRZ) to alternate-mark-inversion (AMI) using the linear filtering effect of silicon microring resonator. Our discussion and analysis in simulation further show that a 10-Gb/s AMI signal with good quality can be obtained by a resonator with a notch depth larger than 25 dB when the 3-dB bandwidth is 0.4 nm.
|
|
| 8. |
- Li, Qiang, et al.
(author)
-
Dense wavelength conversion and multicasting in a resonance-split silicon microring
- 2008
-
In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 93:8
-
Journal article (peer-reviewed)abstract
- We experimentally demonstrate all-optical wavelength conversions in a 10 mu m radius resonance-split silicon microring resonator based on free carrier dispersion effect. The split resonance is caused by the mutual coupling between the two countertraveling modes inside the ring resonator. Dense wavelength conversions are performed at data rates from 500 Mbytes/s to 5 Gbytes/s and a dual-channel wavelength multicasting is realized at a data rate of 1.25 Gbytes/s. The resonance splitting phenomenon opens up opportunities to convert more closely spaced wavelengths, thus effectively increasing the system capacity.
|
|
| 9. |
- Li, Qiang, et al.
(author)
-
Fast light in silicon ring resonator with resonance-splitting
- 2009
-
In: Optics Express. - 1094-4087. ; 17:2, s. 933-940
-
Journal article (peer-reviewed)abstract
- We report experimental demonstration of fast light in an over-coupled ultra-compact silicon ring resonator with resonance-splitting. Strong mutual-coupling induced by the grating inside the ring leads to split resonances and accompanying large anomalous dispersion, thus providing a new approach to realizing fast light in the over-coupled region of the ring resonator. In the experiment, a maximum pulse advancement of 130 ps with low distortion is achieved for a 1-ns signal pulse in a 10-mu m-radius silicon ring resonator. The observed pulse advancement agrees well with the theoretical calculation based on coupled mode theory.
|
|
| 10. |
|
|
