Wide-band-tunable sources using photomixing in laser-assisted field emission

Mark J. Hagmann

doi:10.1117/12.529765

8 April 2004 Wide-band-tunable sources using photomixing in laser-assisted field emission

Mark J. Hagmann

Proceedings Volume 5354, Terahertz and Gigahertz Electronics and Photonics III; (2004) https://doi.org/10.1117/12.529765
Event: Integrated Optoelectronic Devices 2004, 2004, San Jose, CA, United States

Abstract

Quantum theory shows that tunneling electrons have a resonant interaction with a radiation field, and because of this resonance a highly-focused amplitude-modulated laser diode (670 nm, 30 mW) changes field emission current enough to be seen with an oscilloscope. The emitting tip is much smaller than the optical wavelength, so the potential of the tip follows each cycle of the radiation field. Electron emission responds to the total electric field (DC + radiation) with a delay τ < 2 fs, and the current-voltage characteristics of field emission are highly nonlinear. Thus, quantum simulations show that two lasers can cause current oscillations by photomixing, which can be tuned from DC to 500 THz (1/τ) by shifting the frequency offset of the lasers. Microwave prototypes for 1-10 GHz are being tested. The output power is proportional to the resistive part of the impedance that is seen by the current oscillations. However, the electric field at the mixer frequency, which is proportional to this impedance, causes negative feedback to reduce the current oscillations, so there is an optimum impedance for maximum output power. Analyses with equivalent circuits are used to optimize the design. Simulations suggest that 1 μW may be obtained in CW operation, or 10 mW in pulsed operation, using 10 mW laser diodes as the pump sources.

Citation Download Citation

Mark J. Hagmann "Wide-band-tunable sources using photomixing in laser-assisted field emission", Proc. SPIE 5354, Terahertz and Gigahertz Electronics and Photonics III, (8 April 2004); https://doi.org/10.1117/12.529765

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available