Laser-based source for terahertz and millimeter waves

A multi-wavelength laser system, comprising:

• at least two laser chips having different emission wavelengths to permit laser oscillation at two separated wavelengths simultaneously;
• an external cavity in optical communication with the at least two laser chips to receive optical radiation emitted by the at least two laser chips and configured to support simultaneous lasing at the two separated wavelengths;
• and
• a nonlinear medium disposed within the cavity for receiving optical radiation of the two or more separated wavelengths, the nonlinear medium configured to emit radiation having a frequency that is the difference of the frequencies associated with two of the separated wavelengths.

A method for creating lasing in a vertical external cavity surface emitting laser using difference frequency generation, comprising:

• providing at least one laser chip having an intrinsically broadened active region;
• providing an external cavity in optical communication with the laser chip to receive optical radiation emitted by the laser chip and configured to support lasing;
• providing a wavelength selective filter within the external cavity, the wavelength selective filter configured to provide a laser that oscillates at two or more separated wavelengths simultaneously;
• and
• providing a nonlinear medium disposed within the cavity for receiving optical radiation of the two or more separated wavelengths, the nonlinear medium configured to emit radiation having a frequency that is the difference of the frequencies associated with two of the separated wavelengths.