the technology assuring the lower industrial cost is the micro- optics: its cost is mainly due to the cost of the BOM with a relevant contribution due to the work cost. The contribution of CAPEX depreciation is by far smaller with respect to the other technologies. This result clearly explains why the initial phase of the GPON market was dominated by microoptics, and it has even now by far the greater part of the market. Due to the fact that the micro-optics BOM is composed partly of integrated general purpose elements (the laser and the diode in a TCAN package, for example) and partly of more spe- cific elements (the separation filter is an example), the BOM goes down for volumes greater than 100 kpieces, approximately at (a+b/ox), where a and b are two constants, and x 22 0.65. This trend is slower with respect to the trend relative to the hybrid technology, which has much higher costs for small volumes, but decreases faster when the volume increases. In particular, if we consider the case of with an integrated circuit realized in heavily Ge-doped SiO2, where the laser and the photodiode are integrated with a flip chip bonder before wafer cutting, the monolithic chip would be 40% of the component cost at low volumes. The chip cost decreases quite fast with volume, SO that for volumes between 400 and 6300 kpieces, the hybrid integration technology produces the lower cost component. Above 6 million pieces, the completely monolithic technology developed on the InP plat- form starts to be convenient, and from that point on, increasing the volumes it becomes more convenient. Comparing the curve relative to the InP diplexer with the curve relative to the electronic physical protocols processor implemented with an high performance FPGA, it can be seen that the two curves are similar, due to the fact that the cost model is not SO different. The curve relative to the diplexer is moved almost to the right due to the presence of a non- negligible cost of work due to the operations of packaging and fiber coupling that have