Distance measuring confocal microscope

An apparatus for measuring the distance of a set of points on an object from said apparatus, said apparatus comprising:

• polychromatic light source;
• means for focusing light from said source onto said set of points, said means comprising a known amount of longitudinal chromatic aberration such that different wavelengths emitted from said polychromatic light source have different focal lengths in said object, wherein said means for focusing light comprises a substantially achromatic collimator lens;
• and a Fresnel zone plate of known chromatic aberration, said collimator lens providing collimated polychromatic light from said source as input into said zone plate;
• means for filtering the spectrum of light reflected from said set of points;
• and
• means for measuring the spectrum of the light reflected from said object.

A method for determining the depth of a first object embedded in a substantially transparent second object, said substantially transparent second object having a substantially reflective surface, the steps of said method comprising:

• (A) focusing light from a polychromatic light source onto said substantially transparent second object such that each wavelength of light has a distinct focal point;
• (B) filtering the light reflected from said substantially reflective surface, yielding a first reflected wavelength, and from said first object embedded in said substantially transparent second object, yielding a second reflected wavelength;
• (C) measuring the spectrum of the light filtered in step (B);
• (D) correlating throughput intensity peaks from said first reflected wavelength and said second reflected wavelength measured in step (C) to determine the depth of said first object embedded in said substantially transparent second object.

An apparatus for measuring the distance of a set of points on an object from said apparatus, said apparatus comprising:

• polychromatic light source;
• means for focusing light from said source onto said set of points, said means comprising a known amount of longitudinal chromatic aberration such that different wavelengths emitted from said polychromatic light source have different focal lengths in said object, wherein said means for focusing light further comprises a first fiber optic cable;
• means for filtering the spectrum of light reflected from said set of points wherein said means for filtering further comprises a second fiber optic cable;
• and
• means for measuring the spectrum of the light reflected from said object;
• and
• a collimator lens wherein said first fiber optic cable and said second fiber optic cable are positioned slightly off-axis from said collimator lens.