An on-chip broadband radiation source, and methods for its manufacture such that a photonics IC comprises an optical waveguide such as a semiconductor waveguide, a thin III-V material membrane with absorption capability for absorbing an optical pump signal induced in the waveguide. The III-V membrane comprises a LED implemented therein. The photonics IC also comprises a coupling means between the waveguide and the membrane. The device provides a broadband radiation source at a wavelength longer than the wavelength of the transferred radiation. The broadband signal can then be coupled out through the waveguide and used in the chip.