Hi Nagendra,

What type of THz imaging are you trying to use? Using standard imaging techniques you will be bound by the diffraction limit, which is proportional to the wavelength. This will vary depending on whether you are using full field or monochromatic thz systems. In either case 0.1 THz is 3mm in wavelength and 10THz is 0.03mm,

However there are techniques for imaging subwavelength features:

1). Ghost imaging can provide good resolutions [1,2,3]

2). A blanchard style microscope [4]

3). THz SNOM can achieve very good resolution [5]

However all of these techniques are quite experimental.I f you let me know specifics of your setup and what you are trying to achieve maybe i can help!

Please feel free to ask further questions!

1. https://www.osapublishing.org/optica/fulltext.cfm?uri=optica-7-2-186&id=427580

2. https://www.nature.com/articles/s41377-020-0338-4

3. https://www.nature.com/articles/s41467-020-16370-x

4. https://www.osapublishing.org/oe/fulltext.cfm?uri=oe-19-9-8277&id=212743

5. https://pubs.acs.org/doi/abs/10.1021/acs.nanolett.7b01924

Dear Luke Peters,

Thanks for your interest.

I am using Terasense. The THz depth imaging system consists of IMPATT (IMPact ionization Avalanche Transit Time diode)generator with a frequency of 100 GHz and output power of 100/80/100 mw supported by THz imaging cameras with a wide spectral range of 1 THz to 3 THz in addition to HRFZ-SI-H lens of a diameter of 50.8mm, (focal length 40mm), polarizer POL-HDPE-OD of a diameter of 50, range of (0.01 -30 THz).

I have a few questions

1).Your generator is at 0.1THz and your camera has a detection of 1-3THz, is it still detecting well as it is outside of spectral window?

2). what is the spacing between each of the components and what is the size of the beam at the emitter?

3). What is the pixel size on the camera you are using?It is possible the camera itself is also a strong limiting factor.

If we are assume you have a 50mm beam at the lense (the full diameter) you are limited to a ~ 3mm resolution by the generation source and this will be difficult to overcome as it is to do with the source wavelength. The methods to overcome it would be quite involved.

Dear Luke Peters,

Thanks for asking important point and discussion.

Our Terasense camera has a frequency range from 0.05 to 0.7 THz, and pixel model is 1024. Spacing is around 5-10 CM. For more details, can go through my publication list.

Ok, for your specific case the limitation of your generation source will be about 3mm without involved setup design, your camera can handle a resolution of about 1mm without complex methdologies.

As for terahertz in general, in depends on the technique used, each have advantages and disadvantages.

THz GI (a form of thz transmission imaging) has achieved resolutions greater than 6.5um

THz snom (not transmission imaging) has achieved resolutions greater than 2nm

A blanchard style microscope can achiever resolutions greater than 100ums but is probably the simplest of the techniques

Thanks for your nice information regarding resolution by using THz system.