Patent ID: 7869332

Claim:
Solid immersion lens through which a convergent optical beam is intended to pass, made in a material with a refractive index n1, having an effective dioptre ( 26 ) separating from a medium of refractive index n2, the convergent optical beam entering the lens via the effective dioptre ( 26 ), an optical axis (Ax), a virtual object focal point (A) for the convergent optical beam, this virtual object focal point being conjugate with a real image focal point (A′), characterized in that the effective dioptre ( 26 ) is defined by the equation √{square root over (x 2 +y 2 )}−n√{square root over ((x −a) 2 +y 2 )}=L in which: x, y are the coordinates of a point (I) of the effective dioptre ( 26 ) in a Cartesian coordinate system (A, x, y) whose origin is the virtual object focal point (A) and whose abscissa axis is the optical axis (Ax), a is the algebraic distance between the virtual object focal point (A) and its conjugate (A′), this distance being nonzero, L is the optical path separating the virtual object focal point (A) from its conjugate (A′), this optical path being constant and nonzero, n is the ratio of refractive index n1 to refractive index n2, and in that the effective dioptre ( 26 ) is smooth and conjugate (A′) lies downstream of the effective dioptre ( 26 ) for the optical beam.