Summary

Logo for the micro-optic facbrication group, inluding a red laser being focused downMicro-optical systems can be found in medical equipment, laser technologies, the telecommunications industry, photonic integrated circuits, and much more. The production of these optics typically involves custom molding or lithography techniques, which have proven to be reliable. The downside is the long lead times and large prices associated with these methods. With the improvement of additive manufacturing technologies, two photon polymerization (2PP) 3D printers are being used to fabricate these same micro-optics.

Spectrum Lab’s Micro Optics Fabrication Group specializes in the design, simulation, and production of micro-optics using 2PP. This 3D printing technique is enabled by the UpNano NanoOne 1000 3D printer here at Spectrum Lab and is capable of single line resolutions less than 200 nm, with advantageous polymer properties that closely resemble glass.Close up of a printed lens arrayScanning electron microscope image of a structure printed on the tip of a fiber

Currently, the micro-optical development aims to improve interconnects for optical communication applicationsand quantum technologies. Other research areas currently in progress include the fabrication of waveguides and the inclusion of various materials in the standard resins to adjust their optical properties. Each area of research aims to reduce the size, weight, power, and cost of bulk optical equipment or to replace traditional fabrication techniques. 

Capabilities

With the UpNano 3D printer, arbitrary optics can be printed on various substrates including glass slides,bare fiber, connectorized fiber, wafers, and more. A brief list of the printer’s specifications can be found below. 

  • Refractive Index @ 1550 nm: 1.49-1.51 
  • Resolution (Max): <200 nm 
  • Print Speed (Max): 750 mm/s 
  • Print Volume (Max): 40x40x40 mm 

Along with the printer capabilities, a unique workflow has been developed at Spectrum Lab to assist in rapid prototyping and fabrication of micro-optics. In this workflow, height maps of optics generated in either MATLAB or Python can be directly imported into a simulation software or directly turned into an .stl file for Scanning electron microscope image of multiple printed lenses, view edge on3D printing. Inversely, .stl files created in any CAD software are able to be turned into the proper format for simulation. This allows one to verify the optical performance before printing, and drastically improve the time from prototype to final print. 

Personnel

Samuel Fritsch (samuelfritsch@montana.edu) 

Dr. Corey Pearson (coreypearson@montana.edu) 

Graduate Researcher

Katerina Shabalin (Katerina.shabalin@montana.edu)

Publications

  1. Nano-Printed Spiral Phase Plate on Fiber Ferrules for Modal Filtering in Free-Space Optical Communications, Samuel Fritsch, Joshua Dugre, Krishna Rupavatharam, https://doi.org/10.1109/JLT.2026.3685948