Coupling between electromagnetic fields and distinct mechanical states of matter (e.g., Brillioun modes or phonon modes) can mediate energy transfer between electromagnetic waves and the material lattice. Ferroelectric crystals typically show intense optical phonon modes, which also contribute substantially to the nonlinear susceptibility. One such ferroelectric crystal is KTiOPO 4 (KTP), with a large damage threshold, nonlinear coefficient, and transparency range. Moreover, KTP and isomorphs have already been shown to produce cascades of Raman [1] . Recent developments have shown that KTP can be used as an off-axis oscillator for THz generation, mediated by picosecond stimulated polariton scattering (SPS) [2] . Here, we show highly efficient Raman comb generation with nanosecond pulses without an external cavity (contrary to ref. [1] ) in KTP.