Physical considerations for the design of a linear opto-to-RF converter for analog fiber optics

The penetration of fiber optics into CATV systems has created a market for a hybrid integrated opto-to-RF converter. The physical considerations in regard to noise, bandwidth, and nonlinear distortion for this converter are reviewed and implications for packaging are discussed. The market situation that gives rise to the need for such a converter is also discussed. It is pointed out that the single most important item in achieving success in a project such as this is parasitic reduction. This is important at the photodiode, the photodiode interface, and the preamplifier sections. By integrating these functions into a single hybrid structure where special attention has been paid to parasitic reduction, 1000-MHz, 150-channel performance levels can be expected