Laser glass deposition combines the advantageous material properties of fused silica (FS), especially the excellent optical properties and high thermal and mechanical resistance, with the flexibility and design freedom of additive manufacturing. It enables the integration of fiber optic components into monolithic glass chips. The processing of quartz glass, a material that is typically challenging to process, is enabled by a controlled, locally confined energy input utilizing a CO2 laser. Previous welding experiments of light-guiding quartz glass fibers with a core-cladding structure on FS chips resulted in a degradation of the transmission properties of the fibers. In this work, the beam path of the CO2 laser is modified to improve the transmission and to maintain the single-mode properties of the fibers. Rather than being guided directly onto the fiber from above, the laser beam is directed between the fiber and the substrate. The fiber is continuously placed in the created melt pool of the substrate, which enables a material bond with reduced thermal impact on the fiber core. The influence of process parameters on the optical transmission properties of welded fibers is systematically analysed. A reduction in transmission losses and improved preservation of single-mode properties can be observed compared to previous processes. In the same process environment, an innovative laser-based on-chip cleaving process is being developed to create cleaves with end facet angles between 0° and 12°, enabling efficient and versatile coupling strategies and precise on-chip integration of discrete optical components through micro assembly strategies such as pick and place.