Graphene-Based Photonics Devices for Remote Sensing Applications
sensors
Graphene-Based Photonics Devices for Remote Sensing Applications (GSC-TOPS-27)
Growing large area graphene on optical substrates for use in photonics devices
Overview
Currently, the dominant method to generate ultrafast laser pulses passively is the use of semiconductor saturable absorber mirrors (SESAMs). This type of passive mode locker produces exceptional results but is difficult to fabricate, expensive and limited in bandwidth. In contrast, a graphene based saturable absorber is easier to produce and has the advantages of much wider bandwidth, lower saturation intensity, tunable modulation depth, ultrafast recovery time, and much higher optical damage threshold, thus producing higher energies. High energy (10s nJ) and femtosecond pulses with repetition rate on order of 100s MHz have been demonstrated using graphene as a saturable absorber in developing a graphene-based mode-lock device for a laser transmittter. This work has also led to the development of other novel photonics devices.
The Technology
Innovators at NASA Goddard Space Flight Center have developed a process for transferring graphene to suitable optical substrates, as well as tips of optical fiber, by growing large area graphene using a low pressure chemical vapor deposition (LPCVD) technique. In addition to this new development, a second process was also developed for depositing multiple graphene layers on the same substrate. Using these new processes, NASA engineers and scientists have developed a process to make a saturable absorber with single layer, as well as multilayer graphene. Aside from the applications as a laser transmitter, the saturable absorber can be used as a scalable graphene-based bolometer.
Benefits
- Novel method allows the production of clean and large area graphene suitable for use in laser or mode locking
- Allows for simpler production of saturable absorbers for photonics devices than the current state of the art
- Wider bandwidth and lower saturation intensity than the current state of the art
- Enables tunable modulation depth
- Ultrafast recovery time
- Higher optical damage threshold
- Capable of producing higher energies than current state of the art
Applications
- Mode-lock device for laser transmitter
- Graphene-based bolometer
