Apparatus and method for irradiating a medium

An apparatus comprising:

• a first irradiation unit configured to irradiate a medium with an incident wave;
• an ultrasound device configured to focus an ultrasound wave onto a position in the medium such that the incident wave is modulated into a frequency-shifted wave at the position where the ultrasound wave is focused by the ultrasound device;
• a holographic material;
• a second irradiation unit configured to irradiate the holographic material with a reference wave, a frequency difference between the reference wave and the incident wave being exactly or approximately equal to a frequency of the ultrasound wave focused by the ultrasound device, and to record information corresponding to an interference pattern formed by interference between the frequency-shifted wave and the reference wave by the holographic material, and
• a third irradiation unit, after the information is recorded on the holographic material, configured to irradiate the holographic material with a reading wave substantially in a direction opposite to a direction of the reference wave so that the holographic material generates a reconstructed wave to irradiate the medium to retrace trajectory of the frequency-shifted wave to the position where the ultrasound wave is focused by the ultrasound device.

An apparatus comprising:

• a first irradiation unit configured to irradiate a medium with an incident wave;
• an ultrasound device configured to focus an ultrasound wave onto a position in the medium such that the incident wave is modulated into a frequency-shifted wave at the position where the ultrasound wave is focused by the ultrasound device;
• a first detection unit configured to obtain information corresponding to an interference pattern generated by interference between the frequency-shifted wave and a reference wave;
• a second irradiation unit configured to irradiate the first detection unit with the reference wave, a frequency difference between the reference wave and the incident wave being exactly or approximately equal to a frequency of the ultrasound wave focused by the ultrasound device, and
• a generation unit configured to irradiate the medium with a phase conjugation wave of the frequency-shifted wave to irradiate the medium to retrace trajectory of the frequency-shifted wave to the position where the ultrasound wave is focused by the ultrasound device based on the information obtained by the first detection unit.