| http://www.w3.org/ns/prov#value | - at least two lasers operating to respectively produce two beams at a common wavelength; an optical head disposed relative to said lasers to receive said two beams, said optical head including an objective lens fixed at a first position to receive said two beams and a near-field fixed at a second position to receive said two beams so that said objective lens and said near-field lens are fixed relat
|
