Journal: Nature photonics

Article Title: Wavelength-encoded laser particles for massively multiplexed cell tagging

doi: 10.1038/s41566-019-0489-0

Figure Lengend Snippet: a , Schematic of the LPs production process. b , Structure of the epitaxial wafers used for the fabrication of microdisks. c , Lasing wavelength of microdisks (in air) with increasing design diameters varying from 1.9 to 2.04 μm in steps of 10 nm. Shaded box corresponds to the gain region of the semiconductor (In 0.73 Ga 0.27 As 0.58 P 0.42 ); dashed lines are the calculated cavity-mode resonances for a microdisk with a refractive index n = 3.445. d , Lasing wavelength of four groups of microdisks fabricated with different design diameters in 10 nm steps ( N = 100 per group); standard deviation is ~1 nm. e , SEM image of microdisks after detachment. Inset: close-up of a single microdisk. f , Output curve of laser emission versus pump energy for a typical cavity. g , Typical output emission spectrum of a microdisk above threshold ( E p = 20 pJ). h , Gaussian fit of the lasing peak. i , Histogram of the emission wavelengths of N = 794 different microdisks in Matrigel overlaid with the fluorescence of the active material (In 0.53 Al 0.13 Ga 0.34 As).

Article Snippet: Samples embedded in 3D hydrogel matrix was prepared by mixing equal volumes of an aqueous solution of microdisk laser particles (coated or uncoated) with Matrigel (Corning) and incubating for 2 h at 37 °C to allow matrix cross-linking.

Techniques: Refractive Index, Standard Deviation, Fluorescence

Journal: Nature photonics

Article Title: Wavelength-encoded laser particles for massively multiplexed cell tagging

doi: 10.1038/s41566-019-0489-0

Figure Lengend Snippet: a , Normalized fluorescence spectra of the five different semiconductor materials used in this work; wafer A: In 0.80 Ga 0.20 As 0.44 P 0.56 , wafer B: In 0.73 Ga 0.27 As 0.58 P 0.42 , wafer C: In 0.53 Al 0.13 Ga 0.34 As, wafer D: In 0.53 Al 0.09 Ga 0.38 As, and wafer E: In 0.53 Ga 0.47 As 0.92 P 0.08 . b , Calculated resonance wavelengths of WGM modes with mode-order m , for different microdisk diameters between 2.2 to 2.5 μm. Circles represent possible lasing modes obtainable from the five different wafers with microdisk sizes of 2.3 and 2.4 μm, respectively. c , Normalized laser emission spectra of 400 laser particles in a range from 1170 to 1580 nm with an interval of ~1 nm. All laser particles were pumped by a common laser source.

Article Snippet: Samples embedded in 3D hydrogel matrix was prepared by mixing equal volumes of an aqueous solution of microdisk laser particles (coated or uncoated) with Matrigel (Corning) and incubating for 2 h at 37 °C to allow matrix cross-linking.

Techniques: Fluorescence

Journal: Nature photonics

Article Title: Wavelength-encoded laser particles for massively multiplexed cell tagging

doi: 10.1038/s41566-019-0489-0

Figure Lengend Snippet: a , SEM images of microdisks before and after 1, 2 or 3 coating cycles. b , Silica shell thickness versus reaction cycles ( N ≥ 9 each). Mean ± 95% confidence intervals (CI). c , False-colour cross-sectional SEM image of a coated microdisk cut with focused ion beam. d , EDS analysis of different elements along the diameter of a coated microdisk. e , Wavelength shift of a microdisk versus external refractive index, calculated from FDTD simulations for increasing thicknesses of coating. Grey shaded region corresponds to the typical range for cytoplasm refractive index. f , Sensitivity of the microdisk resonance to external refractive index as a function of coating thickness, calculated for small variations around n 1 = 1.37. g , h , Lasing wavelength versus background refractive index for uncoated (g) and 150 nm coated (h) microdisks on glass ( N = 7 each). Empty circles are experimental data, dashed lines are linear fits.

Article Snippet: Samples embedded in 3D hydrogel matrix was prepared by mixing equal volumes of an aqueous solution of microdisk laser particles (coated or uncoated) with Matrigel (Corning) and incubating for 2 h at 37 °C to allow matrix cross-linking.

Techniques: Refractive Index