Integrated nano-optomechanical displacement sensor with ultrawide optical bandwidth.

Area of Science:

• Optomechanics
• Nanotechnology
• Integrated Photonics

Background:

• Optical read-out of motion is crucial for sensing applications.
• Micro- and nano-optomechanical systems offer potential for compact, on-chip motion sensors.
• Current systems face integration challenges due to narrow spectral resonances requiring complex laser setups.

Purpose of the Study:

• To develop a nanomechanical sensor with ultrawide optical bandwidth for practical applications.
• To overcome the limitations of tuneable lasers and external detectors in integrated optical motion sensors.

Main Methods:

• Utilized a nanomechanical, three-dimensional directional coupler.
• Integrated dual-channel waveguide photodiodes for on-chip photocurrent read-out.
• Achieved an ultrawide optical bandwidth of approximately 80 nm.

Main Results:

• Demonstrated small displacement imprecision of 45 fm/Hz^1/2.
• Achieved a large dynamic range exceeding 30 nm.
• The sensor operates with a broad optical bandwidth, removing the need for tuneable lasers.

Conclusions:

• The developed sensor represents a significant step towards practical, fully-integrated nanomechanical sensors.
• The broad bandwidth and on-chip read-out simplify integration and enhance applicability.
• This technology paves the way for compact and efficient optical motion sensing solutions.