Freeform imaging systems:Fermat's principle unlocks"first time right"design

For more than 150 years,scientists have advanced aberration theory to describe,analyze and eliminate imperfections that disturb the imaging quality of optical components and systems.Simultaneously,they have developed optical design methods for and manufacturing techniques of imaging systems with ever-increasing complexity and performanee up to the point where they are now including optical elements that are unrestricted in their surface shape.These so-called optical freeform elements offer degrees of freedom that can greatly extend the functionalities and further boost the specifications of state-of-the-art imaging systems.However,the drastically increased number of surface coefficients of these freeform surfaces poses severe challenges for the optical design process,such that the deployme nt of freeform optics remained limited until today.In this paper,we present a deterministic direct optical design method for freeform imaging systems based on differential equations derived from Fermats principle and solved using power series.The method allows calculating the optical surface coefficients that ensure minimal image blurring for each individual order of aberrations.We demonstrate the systematic,deterministic,scalable,and holistic character of our method with catoptric and catadioptric design examples.As such we introduce a disruptive methodology to design optical imaging systems from scratch,we largely reduce the "trial-and-error",approach in present-day optical design,and we pave the way to a fast-track uptake of freeform elements to create the nextgeneratio n high-end optics.We include a user application that allows users to experience this unique design method hands-on.

Recent progress on optical rogue waves in fiber lasers:status,challenges,and perspectives

Rogue waves(RWs)are rare,extreme amplitude,localized wave packets,which have received much interest recently in different areas of physics.Fiber lasers with their abundant nonlinear dynamics provide an ideal platform to observe optical RW formation.We review recent research progress on rogue waves in fiber lasers.Basic concepts of RWs and the mechanisms of RW generation in fiber lasers are discussed,along with representative experimental and theoretical results.The measurement methods for RW identification in fiber lasers are presented and analyzed.Finally,prospects for future RW research in fiber lasers are summarized.

Optical–digital joint design of refractive telescope using chromatic priors

The conventional optical system design employs combinations of different lenses to combat aberrations, which usually leads to considerable volume and weight. In this Letter, a tailored design scheme that exploits state-of-the-art digital aberration correction algorithms in addition to traditional optics design is investigated. In particular, the proposed method is applied to the design of refractive telescopes by shifting the burden of correcting chromatic aberrations to software. By enforcing cross-channel information transfer in a post-processing step, the uncorrected chromatic aberrations are well-mitigated. Accordingly, a telescope of F-8, 1400 mm focal length, and 0.14° field of view is designed with only two lens elements. The image quality of the designed telescope is evaluated by comparing it to the equivalent designs with multiple lenses in a traditional optical design manner, which validates the effectiveness of our design scheme.