Waveguide based submillimmeter-wave and terahertz variable attenuator

A method of making an attenuator, comprising:

• providing a dielectric material with a pattern of holes;
• depositing a metal coating on the top of the dielectric material;
• coupling an actuator to the dielectric material for controlling a position of the dielectric material, with nanometer resolution, in a waveguide configured and dimensioned to guide an electromagnetic wave having a frequency in a range of 500 gigahertz (GHz) to 1 terahertz (THz),
• providing guidance for controlling the position or a volume of the dielectric material inserted in a waveguide to achieve a desired or pre-determined attenuation of the electromagnetic wave, wherein the providing further comprises:
• providing a silicon wafer including a buried oxide layer;
• thermally oxidizing the silicon wafer to form a first thermal oxide on the silicon wafer depositing photoresist on the first thermal oxide;
• patterning the first thermal oxide with the pattern;
• etching the pattern of the holes using inductively coupled plasma etching;
• deep reactive ion etching the silicon wafer using the first thermal oxide as a first mask and a first side of the buried oxide layer as an etch stop, to define the pattern of holes;
• and
• further comprising:
• machining a first metal block so as to form a first section of a waveguide in the first metal block;
• machining a second metal block so as to form a second section of the waveguide in the second block;
• and
• assembling the attenuator between the first metal block and the second metal block so as to form the waveguide comprising the first section mating with the second section and the attenuator coupled to the waveguide guiding the electromagnetic wave.