Related Experiment Video
Updated: Jun 9, 2026

Direct Linear Transformation for the Measurement of In-Situ Peripheral Nerve Strain During Stretching
Published on: January 12, 2024
Fast and accurate algorithm for the computation of complex linear canonical transforms
Aykut Koç1, Haldun M Ozaktas, Lambertus Hesselink
1Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA. aykutkoc@stanford.edu
Abstract:
A fast and accurate algorithm is developed for the numerical computation of the family of complex linear canonical transforms (CLCTs), which represent the input-output relationship of complex quadratic-phase systems. Allowing the linear canonical transform parameters to be complex numbers makes it possible to represent paraxial optical systems that involve complex parameters. These include lossy systems such as Gaussian apertures, Gaussian ducts, or complex graded-index media, as well as lossless thin lenses and sections of free space and any arbitrary combinations of them. Complex-ordered fractional Fourier transforms (CFRTs) are a special case of CLCTs, and therefore a fast and accurate algorithm to compute CFRTs is included as a special case of the presented algorithm. The algorithm is based on decomposition of an arbitrary CLCT matrix into real and complex chirp multiplications and Fourier transforms. The samples of the output are obtained from the samples of the input in approximately N log N time, where N is the number of input samples. A space-bandwidth product tracking formalism is developed to ensure that the number of samples is information-theoretically sufficient to reconstruct the continuous transform, but not unnecessarily redundant.
Related Concept Videos
Vector Algebra: Method of Components
In many applications, the magnitudes and directions of...
Linear Approximations
Linearization and Approximation
Linear Approximation in Time Domain
For a simple pendulum with a mass evenly distributed along its length and the center of mass located at half the pendulum's length, the...
Fast Fourier Transform
The computational efficiency of the FFT becomes...
Vector Representation of Complex Numbers
Consider a function defined as the product of the complex factors in the numerator divided by the product of the complex factors in the denominator.
