Optical microstructure for fiber optical tweezers

An optical microstructure configured to work with an optical fiber or a different substrate, the optical microstructure comprising:

• a beam converter including a tapered optical guide configured to transform a gaussian optical beam into a first annular optical beam;
• and
• an inverted cone having first and second reflection surfaces, each configured to reflect the first annular optical beam, having a radius R1, so that a resulting second annular optical beam has a radius R2 larger than the radius R1,
• wherein the second annular optical beam includes plural single optical beams that intersect at a given crossing point, outside the optical microstructure, and
• wherein the plural single optical beams form an optical trap.

A fiber optical tweezers for manipulating one or more particles, the fiber optical tweezers comprising:

• an optical fiber having an end that outputs a gaussian optical beam;
• and
• an optical microstructure attached to the end of the optical fiber and configured to receive the gaussian optical beam and generate plural single individual optical beams that act as tweezers,
• wherein the optical microstructure includes,
• a beam converter that transforms the gaussian optical beam into a first annular optical beam,
• an inverted cone that increase a radius of the first annular optical beam to form a second annular optical beam, and
• a prism that transforms the second annular optical beam into a third converging annular optical beam,
• wherein the third converging annular optical beam includes the plural single optical beams that intersect at a given crossing point, outside the optical microstructure, and
• wherein the plural single optical beams form an optical trap.

A method for printing an optical microstructure on an end of an optical fiber for forming a fiber optical tweezers, the method comprising:

• printing on the end of the optical fiber, a beam converter including a tapered optical guide configured to transform a gaussian optical beam into a first annular optical beam;
• printing on the beam converter, an inverted cone having first and second reflection surfaces, each configured to reflect the first annular optical beam, having a radius R1, so that a resulting second annular optical beam has a radius R2 larger than the radius R1;
• and
• printing on the inverted cone, a prism having a reflection surface configured to reflect the second annular optical beam to form a third converging annular optical beam,
• wherein the third converging annular optical beam includes plural single optical beams that intersect at a given crossing point, outside the optical microstructure, and
• wherein the plural single optical beams form an optical trapping.