SnV centres in diamond are a promising candidate for quantum internet applications because of their strong spin-photon interface, long spin coherence times, and insensitivity to electric fields. Integrating them in diamond waveguides could strongly improve entanglement rates and could make for a scalable design. In this thesis, we show using simulations that rectangular <110> waveguides are good candidates for high emitter-waveguide coupling, reaching a maximum of 79%. Optimal dimensions are 250 nm x 120 nm (width x height). This also falls inside the single-mode regime for the emitted light. The measured lifetime limits for the linewidth of Γ = 25 MHz, dephasing of Γ_𝑑 = 10 MHz, and >10 seconds long spectral stability in the bulk diamond sample, together with an APD dark count rate of 171 Hz should lead to a transmission dip around resonance of Δ𝑇/𝑇 = 25%, which we predict using a different simulation. The currently obtained taper coupling from diamond waveguide to optical fiber is approximately 10%. This is probably enough to see the transmission dip, but it needs to be improved for future experiments. Post-selecting SnV centres in waveguides and using Purcell enhancement to boost ZPL emission can further improve these results.