Ever since their invention in 1961, lasers have been used in an ever-growing number of applications. They have since been miniaturized and can now be integrated on microchips alongside electronic transistors. Yet,most are emitting a single color, while many novel and exciting applications, such as LIDAR and extrasolar planet detection require the simultaneous emission of many different colors.
But forcing multicolor emission, while the most natural state of a laser is single color emission, is very challenging such that only low-quality multicolor lasers have been fabricated until now.
Here we propose to apply the concept of spontaneous pattern formation to make chip-scale integrated lasers able to naturally structure light in the time domain and hence generate many different stable frequencies.Lasers are nonlinear systems. And just like other nonlinear systems in nature, such as a zebra’s skin, heated fluids or windblown dunes, they can be brought outside of equilibrium where patterns spontaneously form.In lasers, this process can be precisely controlled such that the patterns (and hence their frequencies) can be chosen. Moreover, multicolor emission then becomes the default state, which is very robust to external perturbations.
This project will hence lead to the generation of ultra-stable multicolor integrated lasers. Their emission can be tuned to cater to specific applications. We plan to use these sources for spectroscopy and THz wave generation.