Happy Tax Day!
This week I added a new capability to Optica EM that vastly expands Optica's capabilies for free-form optical design. This new Optica feature is the result of work that I completed more than ten years ago! The original project was to build a flow-cytometer fluorescence detection system. At the time, I needed to make a five-faceted free-form mirror that served as the heart of a optical multiplexer that directed the detected fluorescent light into five different optical fibers from five laser focal spots collected from a high NA elliptical primary mirror. In addition, the free-form mirror removed the intrinsic optical aberrations present in each of the five optical pathways in order to efficiently couple the light into each multimode fiber. The code development for this special free-form mirror lasted for more than three years!
Until recently, this code simply sat on my hard drive and was not included in Optica. Today, I am happy to announce that I have now integrated this functionality into Optica EM!
The principal function, called FindSurfaceShape, works equally well for free-form reflective, refractive, and (very soon for) diffractive optics! FindSurfaceShape works by tracing a single ray into the entrance aperture of a preliminary optical system. This preliminary optical system uses a flat optic in place of the intended free-form optical surface. This flat optic can be either a lens or a mirror. Next, the ray is rastered across the entrance aperture of the system to sequentially stitch together the continuous three-dimensional free-form surface shape.
Once the design is complete, the free-form optical system can then be modeled in Optica and its surface data can be used to make an actual optical part by any number of different methods such as diamond turning, 3-D printing, or laser ablation. Please visit our Partners page to learn about different venders capable of assisting with this!
Depending on the merit functions defined by the user, FindSurfaceShape can determine the solutions for different free-form shapes which either collimate, focus, or eliminate aberrations for the intended optical system.
Finally, the new FarFieldTransform and NearFieldTransform functions of Optica EM can evaluate the diffracted field performance of the resulting free-form system: such as the opto-mechanical tolerances of coupling efficiency into a single-mode or multi-mode optical fiber.