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Heat-Assisted Magnetic Recording (HAMR) is a well-known technology that uses the concept of a plasmonic antenna to shrink the optical focused spot to sizes of tens of nanometers, in order to overcome the limits of conventional magnetic recording and to reach areal density >1 Tb/in 2 . In this paper, we propose a novel concept that allows to increase a power transfer to the recording media deposited on the patterned substrate that takes a full advantage of the resonant antenna conditions to achieve further intensity enhancement in the gap and consequently high-power transfer to the recording media. Apart from the high field enhancement, the proposed concept ensures uniform field distribution in the gap that translates into uniform and higher temperature in the recording media, which is highly desired in the HAMR technology.

In this paper, germanium metal-semiconductor-metal photodetectors (MSM PDs) are fabricated on Si using a low-temperature two-step deposition technique by RF-PECVD. The photodetectors are optimized to effectively suppress the dark current through the insertion of n-type a-Si:H interlayer between the metal/Ge interface. Tuning the Schottky Barrier Height (SBH) by inserting different thickness of the interlayer is investigated. Results revealed that SBH for electrons and holes can effectively be enhanced by 0.3eV and 0.54eV, respectively. Furthermore, the dark-current (IDark) is suppressed significantly by more than four orders of magnitude. The measured IDark is ∼76 nA for an applied reverse bias of 1.0 V. Additionally, the Ge MSMs structure exhibited a photo responsivity of 0.8A/W at that bias. The proposed low-temperature (<550°C) Ge-on-Si MSM PD demonstrates a great potential for high-performance Ge-based photodetectors in monolithically integrated CMOS platform.

On-chip simultaneous mode and wavelength division-multiplexing (MWDM) is proposed using a tapered directional coupler and multimode interference (MMI) waveguide. A simulation is performed on the two different MWDM architectures, in which, two waveguide eigenmodes and two wavelength channels (1310/1550nm) are multiplexed. One of the proposed devices is compact (6μm x 100μm) and exhibits insertion loss as low as 1.2dB with a cross-talk of (-18dB).