Wavelength-converting device and illumination system using same

An illumination system, comprising:

• a solid-state light-emitting element configured for emitting a light in a first waveband;
• and
• a wavelength-converting device comprising:
• at least a first substrate, wherein each of the first substrate has a first region and at least a first engagement portion;
• a second substrate disposed adjacent to the first substrate, wherein the second substrate has at least a second region and at least a second engagement portion, and the second engagement and the first engagement portion have complementary shapes;
• and
• a first wavelength-converting material disposed on the second region for converting the light in the first waveband into a light in a second waveband,
• wherein the light in the first waveband is transmitted through the first region, the light in the second waveband is reflected by the second region, and the first region and the second region are staggered, so that the first engagement portion and the second engagement portion are engaged and fixed with each other.

A wavelength-converting device, comprising:

• two first substrates, wherein each of the first substrate has two first engagement portions, and a light in a first waveband is transmitted through the first substrates;
• and
• a second substrate disposed between the two first substrates, wherein the second substrate has four second engagement portions, and a light in a second waveband is reflected by the second substrate,
• wherein each of the first engagement portions is corresponding to one of the four second engagement portions, and each first engagement portion and each second engagement portion have complementary shapes, so that each first engagement portion and each second engagement portion are engaged and fixed with each other.