Method for examining bone in vivo, comprises obtaining a laser beam; modulating the laser beam to insert therein photoacoustic frequencies including optical frequencies and acoustic frequencies, the acoustic frequencies being able to give rise to acoustic waves; directing the modulated beam at a bone to cause acoustic waves resulting from the beam to travel through the bone; analyzing received signals from the bone including signals resulting from the acoustic waves, to determine a mineral density and a bone quality for said bone, and thus obtain in-vivo data that can be of assistance to a doctor when diagnosing osteoporosis.