Plasmonic Building Blocks

Phase shifter: provides high-speed phase modulation of light.

• 3-dB EO bandwidth >500 GHz
• Plasmonic slot length range 5 to 25 µm
• Plasmonic slot width typ 100 nm
• Plasmonic losses ~0.36 dB/µm. For a length of 10 µm, one achieves <4 dB insertion loss including photonic to plasmonic converters
• Choice of slot materials
• V_π is a consequence of slot geometry and other parameters

Ring resonator modulator: modulates the optical path length of the ring to shift the resonance peak.

• 3-dB EO bandwidth >170 GHz
• Insertion loss <1.5 dB (in coupler), <6.5 dB (fiber to fiber)
• Drive voltage ~0.6 Vp for 408 Gbps transmission
• Proven temperature stability (published papers)

Antenna: directly converts RF to optical signals.

• ​Direct free-space to optical conversion

• Multiple designs possible for operation from GHz to THz

Mach-Zehnder modulator: separates light into two optical paths; the light traveling in these pathways has its phase modulated before recombination.

• 3-dB EO bandwidth >500 GHz
• Plasmonic slot length range 5 to 25 µm
• Plasmonic slot width typ 100 nm
• No travelling-wave electrodes
• Waveguide losses 3 to 5 dB/cm
Example: in a typical plasmonic chip the waveguides are 1 to 2 mm which leads to <1dB losses

Thermo-optic phase shifter (heater): changes the phase by injecting a current through a resistive materiel above the waveguide.

• Serves to set the operating point to achieve optimal extinction ratio
• On-off ratio (ER) >30 dB
• On-off power ~10 mW

Grating coupler: couples light from a fiber into the PIC from the top side, and vice-versa.

• Insertion loss <2.5 dB​
• Optimized for C-band (1550 nm)
• Available for O-band (1310 nm)