A saturable absorber comprising multiple quantum-well layers (32, 34, 36) of differing thicknesses and separated by barrier layers (38) so as to produce a wide-band absorption. Such a saturable absorber (30) is useful in a hybrid mode-locked laser having an optical cavity defined by two mirrors (10,...http://www.google.com.au/patents/US5265107?utm_source=gb-gplus-sharePatent US5265107 - Broadband absorber having multiple quantum wells of different thicknesses
