Efficient multi-mode to single-mode fiber coupling: introduction

The coupling of the optical signal from a multi-mode to a single-mode fiber is a critical issue in application fields that involve numerical aperture optical systems and high accuracy optical characterization tools, such as astronomy and laser testing. Indeed, such multi-mode to single-mode coupling is virtually impossible without loss of spectral information while keeping an acceptable power output. These articles will be aimed at screening the possible setups for such coupling, and finding the ones that offer the best trade-off…