Figure 4
From: Air-coupled ultrasound detection using capillary-based optical ring resonators
Temporal response of different ultrasound detectors to a 50 kHz air-coupled ultrasound transducer (AirMar AR 50). Transmit ultrasound burst of 100 cycles was generated. All data were averaged 256 times. Response data in (c,d and e) are post-filtered with a bandpass filter with a f 0 = 50 kHz and Δf = 20 kHz. Insets show sinusoidal temporal signals for each detector. (a) Driving voltage input to the 50 kHz transmitting transducer. Sinusoidal burst output with a center frequency of 50 kHz was sent to the transducer. (b) Detected transmission signal from the ring resonator. (c) Post-filtered transmission signal from the ring resonator with a bandpass filter. (d) Post-filtered signal from the 800 kHz ultrasound transducer. (e) Post-filtered signal from the microphone.
