Contents 1. Introduction
Optical technology is expected to play an important role in the next generation industrial or scientific challenges. In time domain, an ultra-short pulse is developed as a key technology for ultra-fast photonics. In space domain, a diffractive optical element with sub-wavelength structure can be easily fabricated by using nanotechnology. Such a recent advance in ultra-fast photonics and nanotechnology suggests that spatial dimensions of an ultrashort pulse and an optical device come to be overlapped and ultra-fast photonics and nanotechnology could go well together in this range (Fig. 1). Thus, physical advancements in optical technologies encourage various kinds of physical parameters to have close interactions between them. Here, one of the most types of pervasive optical signal in the conventional infrastructure is an optical temporal signal. In addition, the conventional infrastructure is still eager to use optical technology. Once any optical signals are connected to spatial channels, various latent techniques in free-space optics could be applied to them. In this sense, one of the indispensable match-maker between temporal and spatial optical signals would be optical data form conversion among time slots, wavelength channels, and 2 dimensional (2D) spatial channels [1]–[3]. In this talk, our works based on 2D time-space conversions are focused on in respect to ultra-fast optical signal processing [4]–[9] and ultra-fast measurement [10]–[13]. Physical matching among various parameters surrounding optical technology
