Contribution to the Improvement of the Correlation Filter Method for Modal Analysis with a Spatial Light Modulator
David Benedicto,
María Victoria Collados,
Juan C. Martín,
Jesús Atencia,
Omel Mendoza-Yero,
Juan A. Vallés
Affiliations
David Benedicto
Departamento de Física Aplicada, Instituto de Investigación en Ingeniería de Aragón (I3A), Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
María Victoria Collados
Departamento de Física Aplicada, Instituto de Investigación en Ingeniería de Aragón (I3A), Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
Juan C. Martín
Departamento de Física Aplicada, Instituto de Investigación en Ingeniería de Aragón (I3A), Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
Jesús Atencia
Departamento de Física Aplicada, Instituto de Investigación en Ingeniería de Aragón (I3A), Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
Omel Mendoza-Yero
Institut de Noves Tecnologies de la Imatge (INIT), Universitat Jaume I, 12080 Castelló, Spain
Juan A. Vallés
Departamento de Física Aplicada, Instituto de Investigación en Ingeniería de Aragón (I3A), Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
Modal decomposition of light is essential to study its propagation properties in waveguides and photonic devices. Modal analysis can be carried out by implementing a computer-generated hologram acting as a match filter in a spatial light modulator. In this work, a series of aspects to be taken into account in order to get the most out of this method are presented, aiming to provide useful operational procedures. First of all, a method for filter size adjustment based on the standard fiber LP-mode symmetry is presented. The influence of the mode normalization in the complex amplitude encoding-inherent noise is then investigated. Finally, a robust method to measure the phase difference between modes is proposed. These procedures are tested by wavefront reconstruction in a conventional few-mode fiber.
