Nano electro-mechanical optoelectronic tunable VCSEL.

Area of Science:

• Optoelectronics
• Nanotechnology
• Laser Physics

Background:

• Vertical-cavity surface-emitting lasers (VCSELs) are crucial for optical communication and sensing.
• Existing VCSELs often lack efficient tunability and miniaturization.
• Nano-electromechanical systems (NEMS) offer potential for novel device functionalities.

Purpose of the Study:

• To report a novel electrostatic actuated nano-electromechanical optoelectronic (NEMO) tunable VCSEL.
• To demonstrate continuous wavelength tuning using a high-index-contrast subwavelength grating (HCG) as a tunable mirror.
• To explore the potential for high-speed operation through device miniaturization.

Main Methods:

• Fabrication of a VCSEL incorporating a movable, single-layer HCG as the top mirror.
• Integration of electrostatic actuation for precise control of the HCG position.
• Characterization of optical emission properties, including single-mode operation and wavelength tuning range.

Main Results:

• Achieved single-mode emission with side-mode suppression ratio (SMSR) >40 dB.
• Demonstrated continuous wavelength tuning of approximately 2.5 nm at room temperature under continuous wave (CW) operation.
• The HCG's small footprint led to a 1000-fold mass reduction, enabling higher resonant frequencies.

Conclusions:

• The developed NEMO tunable VCSEL represents a significant advancement in tunable laser technology.
• The HCG integration provides an effective method for achieving tunable, single-mode emission in VCSELs.
• The device's design holds promise for high-speed, miniaturized tunable laser applications.