Low-Cost Feedback-Insensitive DFB Laser/ Electroabsorption Modulator Package

The design of a feedback insensitive DFB Laser/electroabsorption modulator package is presented. The device is shown to be appropriate for short pulse generation. The performance of the proposed device is numerically checked. Monolithically integrated CW DFB lasers coupled to electroabsorption modulators (EAMs) are one of the best configurations for high speed and low chirp pulse generation [1, 2]. Modulation frequencies up to 40 Gb/s has been achieved and soliton-like shaped pulses of a few picoseconds duration have been successfully generated [2]. However, due to the high sensitivity of DFB lasers to optical feedback, the package window has to be anti-reflection (AR) coated. Moreover, sometimes it is also necessary to include optical isolators which considerably increases the size and the cost of the package. In addition, if the package is coupled to an optical fiber, the latter has to be AR coated or specially cut (tapered). Optical feedback from short external cavities modifies t..