Infrared transparent graphene heater for silicon photonic integrated circuits

Abstract

Thermo-optical tuning of the refractive index is one of the pivotal operations performed in integrated silicon photonic circuits for thermal stabilization, compensation of fabrication tolerances, and implementation of photonic operations. Currently, heaters based on metal wires provide the temperature control in the silicon waveguide. The strong interaction of metal and light, however, necessitates a certain gap between the heater and the photonic structure to avoid significant transmission loss. Here we present a graphene heater that overcomes this constraint and enables an energy efficient tuning of the refractive index. We achieve a tuning power as low as 22 mW per free spectral range and fast response time of 3 µs, outperforming metal based waveguide heaters. Simulations support the experimental results and suggest that for graphene heaters the spacing to the silicon can be further reduced yielding the best possible energy efficiency and operation speed.

Graphene photodetectors with a bandwidth >76 GHz fabricated in a 6″ wafer process line

“…The electronic and optic properties of graphene [4], the two dimensional allotrope of carbon, were studied extensively in the last years [5][6][7][8][9]. Moreover, competitive chipintegrated electro-optical devices like electro-optical modulators [10,11], efficient waveguide heaters [12] and ultrafast photodetectors [13][14][15][16] were fabricated using graphene as active material. The performance of graphene photodetectors on integrated silicon waveguides in terms of speed and sensitivity has improved significantly in the last years and the gap between the performance of graphene and competing technologies is vanishing [17][18][19][20][21].…”

Open-Access Silicon Photonics Platforms in Europe

“…The silicon platform reaches TRL of up to 7 on full-wafer prototyping for ICT devices like transceivers [49], lab on a chip sensors or for hybrid integration of novel materials (i.e. graphene [50], [51]). AMO provides direct access (www.amo.de) to its silicon photonics technology platform and provides support in design and process flow to the end-users.…”

Highly Efficient Silicon Photonic Microheater Based on Black Arsenic–Phosphorus

“…For example, graphene has been extensively investigated worldwide due to its large thermal conductivity and ultrafast response. [18][19][20] Efficient TO tuning has been achieved by graphene microheater assisted by microdisk, [21] photonic crystal, [22] and microring cavity. [23] The tunability of such structures are greatly enhanced by strong light-matter interaction, but at the cost of limited operation bandwidth and much higher latency.…”