Optical manipulation apparatus

An optical manipulation system comprising:

• a device configured to radiate a focused electromagnetic beam in a dielectric host medium having a first refractive index n1 when an incoming electromagnetic wave illuminates a first face of the device, wherein the device comprises:
• a first material having a second refractive index n2 and having a first width W1 along a first direction of extension of the first face;
• and
• a second material in contact with the first material and having a third refractive index n3, wherein the second material has a second width W2 along the first direction,
• where n1<n3<n2, and where W1+W2 is greater than a wavelength λ in the host medium of the incoming electromagnetic wave, the first material and the second material extending along a second direction orthogonal to the first face from the first face up to a radiating face of each material, opposite to the first face, the first material and the second material having respectively a first height H1 and a second height H2 along the second direction, where |H2−H1|≤λ/4;
• wherein the device comprises, when the device is in contact with the dielectric host medium and when the incoming electromagnetic wave illuminates the first face:
• a first contact area between the dielectric host medium and the first material, the first contact area radiating a first jet beam in a near field zone;
• a second contact area between the first material and the second material, the second contact area radiating a second jet beam in the near field zone;
• and
• a third contact area between the second material and the dielectric host medium, the third contact area radiating a third jet beam in the near field zone,
• wherein the focused electromagnetic beam results from a combination of at least two beams among the first jet beam, the second jet beam, and the third jet beam, wherein a direction of propagation of the focused electromagnetic beam is tilted with respect to a direction of propagation of the incoming electromagnetic wave;
• and
• an electromagnetic source configured to generate the incoming electromagnetic wave.

A method comprising:

• trapping or moving micro or nanoparticles in a dielectric host medium,
• wherein trapping or moving the micro or nanoparticles in the dielectric host medium uses a device configured to radiate a focused electromagnetic beam in a dielectric host medium having a first refractive index n1 when an incoming electromagnetic wave illuminates a first face of the device, wherein the device comprises:
• a first material having a second refractive index nz and having a first width W1 along a first direction of extension of the first face;
• and
• a second material in contact with the first material and having a third refractive index n3, wherein the second material has a second width W2 along the first direction,
• where n1<n3<n2, and where W1+W2 is greater than a wavelength λ in the host medium of the incoming electromagnetic wave, the first material and the second material extending along a second direction orthogonal to the first face from the first face up to a radiating face of each material, opposite to the first face, the first material and the second material having respectively a first height H1 and a second height H2 along the second direction, where |H2−H1|≤μ/4;
• wherein the device comprises, when the device is in contact with the dielectric host medium and when the incoming electromagnetic wave illuminates the first face:
• a first contact area between the dielectric host medium and the first material, the first contact area radiating a first jet beam in a near field zone;
• a second contact area between the first material and the second material, the second contact area radiating a second jet beam in the near field zone;
• and
• a third contact area between the second material and the dielectric host medium, the third contact area radiating a third jet beam in the near field zone,
• wherein the focused electromagnetic beam results from a combination of at least two beams among the first jet beam, the second jet beam, and the third jet beam, wherein a direction of propagation of the focused electromagnetic beam is tilted with respect to a direction of propagation of the incoming electromagnetic wave.