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Miniature lasers producing ultrashort phase‐coherent pulses at high repetition rates by stable mode‐locking in ambient conditions can offer unique capabilities in various applications, spanning from microwave photonics to telecom and biological imaging techniques. Here, the operation of graphene mode‐locked lasers based on channel waveguides written by femtosecond and picosecond laser pulses in Ti:sapphire crystals is demonstrated. Trains of pulses of 41.4 fs duration at a 21.25 GHz repetition rate are generated by capitalizing on the formation of solitons in their monolithic resonators through Gires–Tournois interferometers. The latter, allow for effective pulse shaping via tuning of the intracavity group delay dispersion while simultaneously enabling ultralow laser operating thresholds. A number of features of these sources, including their high‐brightness and broad bandwidth, are essential ingredients for …