Research Of Low Cost Multiwavelength Laser For OLT Of WDM-PON

WDM-PON technology has great advantages and potential in extending bandwidth,reducing losses and increasing connecting number of channels, etc., thus becoming thefirst choice for next-generation broadband access network technology. However, the costof tunable and wavelength-sensitive WDM components is quite high for access networksresulting in the limitation for the development of WDM-PON. Thus, to develope networkarchitectures, sub-systems and devices that can reduce the cost of WDM-PONs is crucialfor their successful deployment; Therefore, the development of low-cost multi-wavelengthlight source (an important component of the WDM-PON) to reducing the prices of centraloffice optical line terminal is important to promote the further development of thepopularity of WDM-PON network.In this paper, a low-cost multi-wavelength light source for OLT is selected as theresearch topic. A low-cost gain-chip and AWG based multi-wavelength light source hadbeen designed and finished. The main contents can be summarized as follows:(1)By analyzing the principle, cost and other aspects of multi-wavelength AWG lasers,the advantages and disadvantages compared to other lighting solutions had been introduced.The output wavelengths can be precisely controlled by AWG in this kind of light source,and every wavelength can be controlled and modulated simultaneously, taking into accountthe low price of storage management costs for gain chips, the cost of the entire OLTmodule can be effectively reduced.(2)This paper introduces the principles, numerical analysis methods and theproduction process of Planar Lightwave Circuit. There is a detailed description for thePlanar Lightwave Circuit devices: arrayed waveguide grating. Designing and testing forthe AWG in the multi-wavelength light sources have been completed, and the ideal resultshave been achieved. The small-sized AWG has a free spectral range of greater than30nm.Insertion loss is as low as2dB, and the3dB bandwidth of all the channel is about0.23nm.(3)A packaging solutions had been designed based on hybrid integration technology for the light source. Its mechanical stability and thermal conduction capacity have beenanalysed with simulating method. The final package of the light source had beencompleted. And the packaged device had been tested for its performance characteristics;the threshold current of the AWG multi-wavelength light source is22mA, slope efficiencyis0.19mW/mA, extinction ratio can reach up to10dB with the modulation rate of1.25Gbps. This device shows good operating characteristics and can be used as theWDM-PON OLT multi-wavelength light source.