The problem of collimating ultra-broadband continuum from microstructure fiber

Summary form only given. Ultrashort laser pulse technology plays an important role in the fields of physics, chemistry, biology, etc. Ultrashort pulses allow the study of incredibly fast time scales. More importantly, the broad bandwidths of such pulses, whether the pulses are short or not, are useful for many applications, including communication, coherent control of chemical reaction, ultrahigh-spatial-resolution optical coherence tomography, and optical metrology. Recently, ultra-broadband continuum has been obtained from microstructure fibres. As interesting as the potential applications of the supercontinuum are, the huge bandwidth also implies great intrinsic complexity in maneuvering and even simply collimating the beam. Hardly any optical components are designed to deal with such a broad bandwidth, and reflective optics also have their limitations. The problem is still to be solved, and we will discuss the pros and cons of several different methods in the following section.