Wavelength-stabilized broadband light source

An optical fiber sensor system comprising:

• a broadband semiconductor light source configured to emit an output beam whose power is distributed over an output spectrum which defines a bandwidth;
• an optical edge filter arranged to receive a portion of the output beam and divide it by transmission and reflection into short-wavelength and long-wavelength components, where the optical edge filter has a transition range over which the amount of the received portion of the output beam transmitted relative to the amount reflected by the optical edge filter varies as a function of wavelength over at least a portion of the bandwidth of the broadband semiconductor light source including a cross-over wavelength at which the amount of the output beam transmitted and reflected is equal;
• first and second photodetectors each arranged to receive one of the wavelength components reflected and transmitted by the optical edge filter and configured to output respective first and second photodetector signals indicative of the power of the wavelength component received;
• and
• an output element,
• wherein the broadband semiconductor light source, the optical edge filter, the first and second photodetectors and the output element form a light source module, and
• wherein the output beam exits the light source module through the output element, and the system further comprising:
• an optical fiber providing a sensing function in optical communication with the output element so as to receive light from the output beam.