All-optical graphene oxide humidity sensors

Area of Science:

• Optoelectronics
• Materials Science
• Sensor Technology

Background:

• Graphene oxide (GO) possesses unique optical properties influenced by environmental factors.
• Optical sensors offer advantages in sensitivity and response time for humidity detection.
• Developing novel materials for advanced optical sensing applications is crucial.

Purpose of the Study:

• To design and fabricate a graphene oxide-based optical humidity sensor.
• To investigate the optical characteristics of GO for humidity sensing.
• To evaluate the performance of the proposed GO optical humidity sensor.

Main Methods:

• Graphene oxide (GO) film was prepared using the drop-casting technique.
• The GO film was coated onto a SU8 polymer channel waveguide.
• Optical absorption at 1550 nm was measured under varying relative humidity conditions.

Main Results:

• The GO-based sensor exhibited high transverse electric (TE) mode absorption at 1550 nm.
• Absorption decreased with increasing ambient relative humidity due to changes in GO dielectric properties.
• A rapid response time of less than 1 second was observed.
• Linear response of 0.553 dB/% RH was achieved in the 60% to 100% RH range.

Conclusions:

• The developed GO-based optical sensor effectively detects humidity.
• The sensor exhibits high sensitivity, fast response, and linear characteristics.
• GO is a promising material for developing advanced optical humidity sensors.