Optical excitation of atomic force microscopy cantilever for accurate spectroscopic measurements

Yoichi Miyahara, Harrisonn Griffin, Antoine Roy-Gobeil, Ron Belyansky, Hadallia Bergeron, José Bustamante & Peter Grutter
EPJ Techniques and Instrumentation volume, 7 2 (2020)
DOI: epjti/s40485-020-0053-9

Three years after defending my PhD thesis, here's a follow-up paper to its instrumentation chapter. It presents the optical excitation system used to perform accurate spectroscopic measurements. It contains new contributions from several co-authors I had the pleasure to work with during my time at McGill. I want to give special thanks to Harrisonn Griffin and Yoichi Miyahara for bringing this one to the finish line while I'm busy working on plotly!

Here's a link to the full article in PDF

Some highlights

Schematic diagram of the experimental setup

Figure 1. Schematic diagram of the experimental setup. Two laser lights from Laser diode 1 (1550 nm) and Laser diode 2 (1310 nm) are combined with a filter Wavelength Division Multiplexer (FWDM). The combined light is launched into a single-mode optical fiber. While a fraction of the light is reflected at the fiber-vacuum interface, the rest of the light which comes out of the fiber is reflected on the back side of the cantilever and goes back into the fiber. Only the 1550 nm laser can pass through the filter WDM and reach the photo diode

Amplitude and phase frequency responses of the AFM cantilever excited by optical excitation (red) and piezo excitation (blue) measured at 4.5 K.

Figure 4. Amplitude and phase frequency responses of the AFM cantilever excited by optical excitation (red) and piezo excitation (blue) measured at 4.5 K. Note the spurious mechanical resonances in the piezo excitation which arise from vibrations in the microscope body

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