Our optical vortex phase plate is fabricated directly on top of an optical fiber. This makes it extremely easy to use. No need for optical alignment or bulky free-space optics. Simply connect the fiber to your laser of choice and the output is a vortex beam!
An optical vortex – also known as twisted light – is a special type of beam that carries orbital angular momentum. The phase of such beam changes with the azimuthal angle. As a result, in the center of a beam a phase singularity appears. The singularity leads to a characteristic donut-shape beam with a zero intensity on the axis. The two main features of the beam, angular momentum and donut shape, result in two types of applications. Angular momentum is used in telecommunications to transmit information or in optical trapping to rotate microparticles. Zero intensity at the axis is used in STED microscopy to achieve subdiffraction imaging. Typically, vortex beam is created using either bulky and expensive spiral phase plate or an even bulkier optical setup with a spatial light modulator. Instead, our approach is to use nanoimprint technology to fabricate spiral phase plate directly on the edge of the fiber.
Vortex phase plate on fiber specification:
|Wavelength, nm||Beam divergence full angle, degrees||Topological charge||Refractive index of the phase plate||Fiber||Connector|
|405 – 1550*||3 – 15||1 – 4||1.51 – 1.70||Single mode||FC/PC, FC/APC|
*Optical measurements are only available for 405-1100 nm wavelength range
By combining the vortex phase plate with our Fiber Collimator, we can control the beam divergence of the vortex beam that comes out of the optical fiber. Below you can see the far field from the fiber generating optical vortex with M=1 topological charge. The only difference between the fibers is the beam divergence. Choosing output angle of the beam makes it easy to match the vortex fiber with your optical setup.
Applications of the optical vortex:
- STED microscopy
- Optical trapping
Advantages of our vortex phase plate:
- No optical alignment is necessary
- Stability and reproducibility
- Ease of integration
- Small size
Contact us to purchase fiber vortex phase plate or to customize them for your application.