  Controlling the directionality of spin waves is a key ingredient in
wave-based computing methods such as magnonics. In this paper, we demonstrate
this particular aspect by using an all-optical point-like source of continuous
spin waves based on frequency comb rapid demagnetization. The emitted spin
waves contain a range of k-vectors and by detuning the applied magnetic field
slightly off the ferromagnetic resonance (FMR), we observe X-shaped caustic
spin-wave patterns at $70^{\circ}$ propagation angles as predicted by theory.
When the harmonic of the light source approaches theFMR, the caustic pattern
gives way to uniaxial spin-wave propagation perpendicular to the in-plane
component of the applied field. This field-controlled propagation pattern and
directionality of optically emitted short-wavelength spin waves provide
additional degrees of freedom when designing magnonic devices.
