Fig. 2.

The optical coherence elastography (OCE) system comprises a microliter air pulse stimulator to induce mechanical waves in the sample and a common-path OCT imaging system to track the resulting dynamics of elastic wave propagation. The distance between the stimulation and measurement points was 0.15 mm. SLD: a 1290 ± 40-nm superluminescent laser diode. Common-path construction was formed using an acrylic reference plate, 4 mm thick, to provide a reference plane so that both the sample and the reference arms shared the same optical path [19]. Linear-k spectrometer was formed by a grating and a prism to disperse the interference spectrum optically in the k domain so that the interference signals can be processed directly (without any digital interpolation) via Fourier transform to acquire the depth profiles (A-scans) [55,57,58].