Delgoffe, Antoine MaximeNazir, SaoodHakobyan, SargisHönninger, ClemensBellouard, Yves2023-09-262023-09-262023-09-26202310.1364/OPTICA.496503https://infoscience.epfl.ch/handle/20.500.14299/201062Free-space optics allows for design freedom and control, but miniaturization and manufacturability are limited. Here, we present a method for manufacturing complex miniaturized free-space optical systems that combines contactless femtosecond laser-activated alignment with femtosecond laser 3D manufacturing of a substrate incorporating optomechanical elements. Specifically, we demonstrate a palm-sized, all-glass GHz femtosecond laser cavity, whose alignment and lasing operation are permanently tuned in a contactless manner via laser–matter interaction using another femtosecond laser. The manufactured Yb:KYW oscillator shows self-starting mode-locking with a diffraction-limited beam and outputs a stable train of solitons with 182 fs pulse width at 1.0925 GHz repetition rate, for 725 mW incident pump power.Femtosecond laserLaser packagingPrecision opticsGHz oscillatorFine positioningtext::journal::journal article::research article