Ultra-compact 8 × 8 optical space switch with generic InP technology

A broadband and fast optical space switch is a crucial part of optical networks. A broadband, compact, and fast monolithically integrated InP/InGaAsP strictly nonblocking optical space switch based on semiconductor optical amplifiers (SOA) gates has been designed, fabricated via the generic InP technology and characterized. The component losses, gain, and switching properties of the optical switch are analysed. The gain of three SOAs on a path was measured to be 31 dB on average and is enough to balance component losses whenever a reasonable number of waveguide crossings is encountered (< 25). An optical signal to noise ratio (OSNR) and extinction ratio (ER) as large as 42.4 dB and 37.6 dB, respectively, are obtained in the best path. The performance can be further improved with optimized optical routing and design of lower loss crossings. These results pave the way to scale the switch to higher port counts by using this switch as a building block on a modular basis. Additionally, the use of ultra-compact bends and the number of components integrated on this single chip also shows to be promising for achieving compact optical switches in generic technology.