A laser includes a Ti:sapphire gain-medium in the form of a thin-disk. The probe pulse comprises a plurality of wavelength components in a bandwidth, so that each temporal portion of the converted pulse corresponds to and comprises one of the wavelength components. An etched diffraction grating located at the end of the optical fiber taper de-multiplexes optical signals. The maximum generated electric power of the first rotary electric machine is substantially equal to the maximum output power of the second rotary electric machine. A buffer layer is formed on a portion of the liner layer that is formed on a sidewall of the trench and exposed after the flowable insulation layer is recessed. Amplitude data is acquired from the insonified object at the fundamental frequency and at a second harmonic of the fundamental frequency, and a non-linear acoustic image is generated from the amplitude data at the fundamental frequency and the second harmonic frequency.