Optomechanical transducer-based soft and high frequency nanoscale cantilever for atomic force microscopy

Abstract

We introduce an optomechanical transducer-based nanoscale cantilever probe for atomic force microscopy (AFM). The high optical quality factor of the microdisk resonator enables detection of the nanoscale cantilever motion with high sensitivity. The low stiffness ( 1 N/m) and high frequency (above 4 MHz) nanoscale cantilever provides both a wide bandwidth for fast motion detection and a high force sensitivity. We demonstrate the capabilities of the device in AFM for fast scanning (nominal 30 μm × 30 μm, 39.06 Hz line rate, 2.93 mm/s tip speed) with a fast settling time (< 2 μs). Furthermore, the detection of photo-thermal induced resonance (PTIR) signals at a 50 nm thick polymer film is also demonstrated.