Wavelength conversion device and light source system

A light source system, comprising:

• the wavelength conversion device, the wavelength conversion device comprising:
• a substrate;
• a first light-emitting portion provided on the substrate, wherein the first light-emitting portion comprises a first light guiding region and a counterweight region arranged on a same layer as the first light guiding region, the first light guiding region is configured to guide first light, and the counterweight region is configured to balance weight distribution of the wavelength conversion device into substantially uniform distribution, and wherein the first light guiding region comprises a diffuse reflection layer;
• and
• a second light-emitting portion provided on a same side of the substrate as the first light-emitting portion, wherein the second light-emitting portion comprises a conversion region configured to convert at least a part of excitation light into excited light when the conversion region receives the excitation light, and configured to emit the excited light;
• an excitation light source configured to emit the excitation light to the second light-emitting portion, at least a part of the excitation light being converted into excited light by the conversion region and then being emitted therefrom;
• and
• a first light source configured to emit the first light to the first light guiding region.