Active offset-frequency control of optical frequency comb via sum-frequency mixing of passively mode-locked laser and continuous-wave laser.

We propose a method for actively controlling the frequency of an optical frequency comb (OFC) using sum-frequency generation (SFG) with a nonlinear crystal. For the first time, OFC generation was experimentally demonstrated via sum-frequency mixing of a narrowband continuous wave (CW) laser and a passively mode-locked fiber laser. By adjusting the optical frequency of the CW laser, we successfully controlled the offset-frequency of the SFG-OFC, which was mapped from the OFC of the pulse pump laser.

Retrieval of the extreme values under deadline constraints in wireless sensor networks.

We consider a problem of retrieving the extreme value among sensed data under deadline constraints in wireless sensor networks with potential applications to alarm systems. The sensed data is mapped to a score which we adopt as a unified measure of the relative urgency of the data. The objective is to retrieve the data with the maximum score.