The energy released in a nuclear fusion reaction, consider: <mrow class="MJX-TeXAtom-ORD">

The alpha particles that are produced have a high kinetic energy, this high kinetic energy will translate to a high temperature, in fact the sun has a very high temperature in the core of 10 to 15 million kelvin. These very hot bodies will emit black body radiation which is light and do not directly produce photons as for example an laser. The sun is basically a very hot light bulb. The wavelength and intensity that a black body emits is determined by it's temperature according to the Planck's law:
$B_{\nu }(\nu ,T)=\frac{2h{\nu }^3}{c^2}\frac{1}{e^{\frac{h\nu }{k_{\mathrm{B}}T}}-1}.$

in addition to the kinetic energy of the fusion reaction products created in the core of the sun, electromagnetic energy is also released in the form of gamma ray photons which propagate out from the core. they then experience nearly countless collisions with nuclei on their way out. Many of those collisions are inelastic in the sense that energy is imparted to the nuclei and subtracted from the photons, so that by the time the photons make it out to the edge of the photosphere and propagate away into space, their per-photon energy has been reduced and distributed into the blackbody spectrum we observe from here.