<blockquote>
<p>Is there an equivalent of CCD/CMOS sensors for non-optical wavelengths?</p>
</blockquote>
<p>Yes!</p>
<p><em><strong>But before I mention them</strong></em> have a look at some &quot;radio&quot; focal planes of discrete receivers to show what I think you are not asking about first:</p>
<p><strong>note:</strong> click images for full size</p>
<ul>
<li>from <a href="https://astronomy.stackexchange.com/q/21121/7982">How do ASKAP&#39;s focal plane phased array feeds interact with the entire array phasing?</a></li>
</ul>
<blockquote>
<p><strong>below x2:</strong> Cropped from <a href="https://en.wikipedia.org/wiki/File:CSIRO_ScienceImage_2161_Close_up_of_a_radio_astronomy_telescope_with_several_more_in_the_background.jpg" rel="nofollow noreferrer">CSIRO ScienceImage 2161 Close up of a radio astronomy telescope with several more in the background</a>.</p>
<p><a href="https://i.sstatic.net/Rqq4X.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Rqq4Xm.jpg" alt="cropped from &quot;CSIRO ScienceImage 2161 Close up of a radio astronomy telescope with several more in the background&quot;" /></a></p>
</blockquote>
<ul>
<li>from <a href="https://astronomy.stackexchange.com/q/16237/7982">What is the highest granularity focal-plane array on a dish radio telescope? Or is this the ONLY ONE?</a></li>
</ul>
<blockquote>
<p><a href="https://i.sstatic.net/lE5ke.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/lE5kem.png" alt="Parkes Radio Telescope 21cm Focal Plane Array in 1997" /></a> <a href="https://i.sstatic.net/T15Ao.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/T15Aom.png" alt="Parkes Radio Telescope 21cm Focal Plane Array in 1997" /></a>
<a href="https://i.sstatic.net/URU8o.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/URU8om.jpg" alt="enter image description here" /></a></p>
<p><strong>Above:</strong> Superposition of the half-power beam widths of the 13-element array of the Parkes 21-cm Mutlibeam Receiver, as used in [a study of a Fast Radio Bursters]<a href="http://arxiv.org/abs/1602.07477" rel="nofollow noreferrer">http://arxiv.org/abs/1602.07477</a>.</p>
</blockquote>
<h3>Okay, now what you are asking about; &quot;equivalent of CCD/CMOS sensors for non-optical wavelengths&quot;:</h3>
<p>The first thing that comes to mind are bolometer and calorimeter chips. These are devices where the top layer absorbs photons, sometimes sensitive to a single photon, converting its energy to heat. The device directly below it in the same pixel is something very sensitive to tiny changes in temperature or a single thermal pulse, respectively.</p>
<p>For very low energy photons of microwave frequencies, there are transition-edge sensors like the ones used in the focal plane of the <a href="https://en.wikipedia.org/wiki/South_Pole_Telescope" rel="nofollow noreferrer">South Pole Telescope</a>. For the newest focal plane array SPT-3G camera:</p>
<blockquote>
<p>The camera consists of over 16,000 detectors, split evenly between 90, 150, and 220 GHz.</p>
</blockquote>
<p>For a good review of the underlying technology, start with:</p>
<ul>
<li>Wikipedia's <a href="https://en.wikipedia.org/wiki/Transition-edge_sensor" rel="nofollow noreferrer">Transition-edge sensor</a></li>
<li>MIT's Figueroa Group (Experimental Cosmology and Astrophysics Laboratory) <a href="http://web.mit.edu/figueroagroup/ucal/ucal_tes/" rel="nofollow noreferrer">Transition Edge Sensors (TES)</a></li>
<li><a href="https://pole.uchicago.edu/public/Publications.html#h.u3a4w2pid6pe" rel="nofollow noreferrer">South Pole Telescope Technical Publications</a></li>
</ul>
<p><a href="https://i.sstatic.net/rKmdX.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/rKmdXm.jpg" alt="A single SPT-3G hexagonal detector wafer with flexible cables that connect the detectors to the rest of the readout chain. Each black spot on the wafer is an antenna that couples the incoming light to six different TES detectors (three bands and orthogonal polarizations) from Amy Bender's Github" /></a></p>
<p>(click image for full size)</p>
<blockquote>
<p>A single SPT-3G hexagonal detector wafer with flexible cables that connect the detectors to the rest of the readout chain. Each black spot on the wafer is an antenna that couples the incoming light to six different TES detectors (three bands and orthogonal polarizations).</p>
</blockquote>
<p>Source: Amy Bender's Github <a href="https://benderan.github.io/spt3g/spt3g.html" rel="nofollow noreferrer">SPT-3G</a></p>
<p>From:</p>
<ul>
<li>J. A. Sobrin et al. (2022) <a href="https://arxiv.org/abs/2106.11202" rel="nofollow noreferrer">The Design and Integrated Performance of SPT-3G</a></li>
</ul>
<p><a href="https://i.sstatic.net/WYGF8.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/WYGF8m.jpg" alt="Figure 3. (Left) Picture of the SPT-3G detector array (consisting of ten detector modules) and supporting sub-kelvin architecture." /></a> <a href="https://i.sstatic.net/Cjv7B.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Cjv7Bm.jpg" alt="Figure 4. Scanning electron microscope micrograph of an SPT-3G pixel, showing the sinuous antenna at the center surrounded by six TES bolometers as well as various test structures." /></a></p>
<p>(click images for full size)</p>
<blockquote>
<p>Figure 3. (Left) Picture of the SPT-3G detector array (consisting of ten detector modules) and supporting sub-kelvin architecture. The thermal stages are mechanically supported by a Graphlite truss structure that stands off the UC, IC, and 1K stages from a mounting ring at 4K. Each stage is machined from aluminum alloy 6061 and gold-plated to promote thermal conductivity across the components and between interfaces. The thermal stages are coupled to the sorption refrigerator using pressure-bonded annealed OFHC braided copper straps (Sobrin et al. 2018).</p>
</blockquote>
<blockquote>
<p>Figure 4. Scanning electron microscope micrograph of an SPT-3G pixel, showing the sinuous antenna at the center surrounded by six TES bolometers as well as various test structures. The bolometers corresponding to one polarization state have been labeled with their respective observing bands.</p>
</blockquote>
<hr />
<p>This is from NASA's <a href="https://www.nasa.gov/jpl/multimedia/superconducting-detectors-pia17993" rel="nofollow noreferrer">Superconducting Detectors for Study of Infant Universe</a></p>
<blockquote>
<p>The BICEP2 telescope at the South Pole uses novel technology developed at NASA's Jet Propulsion Laboratory in Pasadena, Calif.  The focal plane shown here is an array of devices that use superconductivity to gather, filter, detect, and amplify polarized light from the cosmic microwave background -- relic radiation left over from the Big Bang that created our universe.</p>
<p>The microscope is showing a close-up view of one of the 512 pixels on the focal plane, displayed on the screen in the background.</p>
<p>Each pixel is made from a printed antenna that collects polarized millimeter-wavelength radiation, with a filter that selects the wavelengths to be detected. A sensitive detector is fabricated on a thin membrane created through a process called micro-machining.</p>
</blockquote>
<p>Note that BICEP-3 and BICEP Array will supersede this technology, at least in total pixel count.</p>
<p><a href="https://i.sstatic.net/pqcHW.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/pqcHWm.jpg" alt="The BICEP2 telescope at the South Pole uses novel technology developed at NASA's Jet Propulsion Laboratory in Pasadena, Calif.  The focal plane shown here is an array of devices that use superconductivity to gather, filter, detect, and amplify polarized light from the cosmic microwave background" /></a></p>
<p>(click for full size image)</p>
<p>See also</p>
<ul>
<li><a href="https://orca.cardiff.ac.uk/id/eprint/130169/1/2002.05228.pdf" rel="nofollow noreferrer">Design and Performance of the First BICEP Array Receiver</a></li>
</ul>
<hr />
<p><a href="https://astronomy.stackexchange.com/a/50743/7982">@ConnorGarcia's answer</a> highlights the infrared telescope JWST's focal plane detectors.</p>
<p>See:</p>
<ul>
<li>Goddard Space Flight Center's JWST <a href="https://www.jwst.nasa.gov/content/about/innovations/infrared.html" rel="nofollow noreferrer">Infrared Detectors</a></li>
</ul>
<p>NIRCam, NIRSpec and FGS/NIRISS use mercury-cadmium-telluride (HgCdTe) semiconductor pixel arrays that convert lower energy infrared photons (here 0.6 yo 6 um) to carriers just like silicon sensors do, but they sit above a matching silicon CCD that accepts the charge produced in the low band gap material and do the necessary shifting for readout and transfer to the traditional charge amplifiers and ADCs.</p>
<p>MIRI however uses an arsenic-doped silicon array, based on impurity band conduction rather than the bulk silicon's conduction bands. G. H. Rieke et al. (2015) <a href="https://arxiv.org/abs/1508.02362" rel="nofollow noreferrer">The Mid-Infrared Instrument for the James Webb Space Telescope, VII: The MIRI Detectors</a> begins:</p>
<blockquote>
<p>The detectors of choice for the 5 - 28 µm range are arsenic-doped silicon impurity band conduction (Si:As IBC) devices. They have extensive space flight heritage, for example, arrays of these devices were used in all three Spitzer instruments (IRAC: Hora et al. (2004a); IRS: van Cleve et al. (1995), Houck et al. (2004); and MIPS: Gordon et al. (2004)), in WISE (Mainzer et al. 2008), in MSX (Mill et al. 1994) and in Akari (Onaka et al. 2007). The focal planes on these missions have demonstrated high detective quantum efficiencies, low dark current and relative freedom from other spurious signals, excellent photometric performance, and resistance to the effects of cosmic radiation. Similar detector arrays were selected for the Mid-Infrared Instrument (MIRI) on JWST.</p>
</blockquote>
<p><a href="https://i.sstatic.net/mnbTu.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/mnbTum.jpg" alt="Figure 1: A James Webb Space Telescope Near Infrared Camera (NIRCam) detector with optical baffles removed. Light is collected in the purple mercury-cadmium-telluride film. The film is pixelated, although the individual pixels are far too small to be seen by eye here. Credit: University of Arizona/NASA" /></a></p>
<p>(click image for full size)</p>
<blockquote>
<p>Figure 1: A James Webb Space Telescope Near Infrared Camera (NIRCam) detector with optical baffles removed. Light is collected in the purple mercury-cadmium-telluride film. The film is pixelated, although the individual pixels are far too small to be seen by eye here. Credit: University of Arizona/NASA</p>
</blockquote>
<p>Source: Goddard Space Flight Center's JWST <a href="https://www.jwst.nasa.gov/content/about/innovations/infrared.html" rel="nofollow noreferrer">Infrared Detectors</a></p>

CC BY-SA 4.0
2022-10-14T09:09:17.143Z
NIRCam has nothing to do with radio astronomy. BICEP2 is a microwave experiment. The South Pole Telescope is mainly sub-mm.
ProfRob
CC BY-SA 4.0
2022-10-14T11:58:22.400Z
@ProfRob a continuum of technologies for a continuum of wavelengths.
uhoh
CC BY-SA 4.0
2022-10-14T01:43:49.920Z
2022-10-14T01:56:17.410Z
2022-10-14T01:56:17.410Z
uhoh
<p>You could use an array of radio telescopes like a CCD, by pointing each dish at a different element of a sky grid, with each grid element as wide as the effective antenna beamwidth. I have never heard of an array being used in this way.  Practically, I think interferometry is always used for radio telescope arrays, given the higher sensitivity and resolution possible.</p>
<p>As an example of other non-optical astronomy sensors, the JWST's NIRCam is &quot;analogous to CCDs found in ordinary digital cameras&quot; according to this <a href="https://www.jwst.nasa.gov/content/observatory/instruments/nircam.html" rel="nofollow noreferrer">NASA website</a>.</p>

CC BY-SA 4.0
2022-10-13T19:26:49.073Z
2022-10-13T19:26:49.073Z
Connor Garcia
<p>Is there an equivalent of CCD/CMOS sensors for non-optical wavelengths?</p>
<p>(not looking for alternative/indirect methods like interferometry)</p>

CC BY-SA 4.0
2022-10-13T11:37:52.837Z
Non-optical covers all sorts of wavelengths. I think you need to specify a wavelength range.
ProfRob
CC BY-SA 4.0
2022-10-13T15:39:25.560Z
Do you mean something like an infrared camera?
Greg Miller
CC BY-SA 4.0
2022-10-13T18:02:29.393Z
Would you count ALMA as a 2D sensor? It is an array of receiving elements (and each one has two polarizations measured).
Jon Custer
CC BY-SA 4.0
2022-10-13T21:18:20.347Z
@ProfRob Radio waves, in this case
2080
CC BY-SA 4.0
2022-10-14T05:50:51.487Z
Still not precise enough. What is a radio wave, what is a microwave? Is 1mm a radio wave?
ProfRob
CC BY-SA 4.0
2022-10-14T07:38:42.233Z
@ProfRob is there really such thing as "precise" when talking about the dividing lines between "radio" and "microwaves" and "far infrared"? cf. [Is Sofia a radio telescope proper?](https://astronomy.stackexchange.com/q/43398/7982)
uhoh
CC BY-SA 4.0
2022-10-14T09:06:17.320Z
@uhoh No. That is my point. The OP needs to define what they mean.
ProfRob
<radio-astronomy><radio-telescope>
In radio astronomy, do two dimensional sensors exist?
2080
# In radio astronomy, do two dimensional sensors exist?

(Asked by: username_0 on 2022-10-13)

Is there an equivalent of CCD/CMOS sensors for non-optical wavelengths?

(not looking for alternative/indirect methods like interferometry)

**Tags:** radio-astronomy, radio-telescope

> **Comments:**
> **username_1**: Non-optical covers all sorts of wavelengths. I think you need to specify a wavelength range.  
> **username_2**: Do you mean something like an infrared camera?  
> **username_3**: Would you count ALMA as a 2D sensor? It is an array of receiving elements (and each one has two polarizations measured).  
> **username_0**: @username_1 Radio waves, in this case  
> **username_1**: Still not precise enough. What is a radio wave, what is a microwave? Is 1mm a radio wave?  
> **username_4**: @username_1 is there really such thing as "precise" when talking about the dividing lines between "radio" and "microwaves" and "far infrared"? cf. [Is Sofia a radio telescope proper?](https://astronomy.stackexchange.com/q/43398/7982)  
> **username_1**: @username_4 No. That is my point. The OP needs to define what they mean.  

---

## 2 answers

### Answer by username_4 on 2022-10-14. Score: 3

> Is there an equivalent of CCD/CMOS sensors for non-optical wavelengths?

Yes!

***But before I mention them*** have a look at some "radio" focal planes of discrete receivers to show what I think you are not asking about first:

**note:** click images for full size

* from [How do ASKAP's focal plane phased array feeds interact with the entire array phasing?](https://astronomy.stackexchange.com/q/21121/7982)

> **below x2:** Cropped from [CSIRO ScienceImage 2161 Close up of a radio astronomy telescope with several more in the background](https://en.wikipedia.org/wiki/File:CSIRO_ScienceImage_2161_Close_up_of_a_radio_astronomy_telescope_with_several_more_in_the_background.jpg).
>
> [![cropped from "CSIRO ScienceImage 2161 Close up of a radio astronomy telescope with several more in the background"](https://i.sstatic.net/Rqq4Xm.jpg)](https://i.sstatic.net/Rqq4X.jpg)

* from [What is the highest granularity focal-plane array on a dish radio telescope? Or is this the ONLY ONE?](https://astronomy.stackexchange.com/q/16237/7982)

> [![Parkes Radio Telescope 21cm Focal Plane Array in 1997](https://i.sstatic.net/lE5kem.png)](https://i.sstatic.net/lE5ke.png) [![Parkes Radio Telescope 21cm Focal Plane Array in 1997](https://i.sstatic.net/T15Aom.png)](https://i.sstatic.net/T15Ao.png)
> [![enter image description here](https://i.sstatic.net/URU8om.jpg)](https://i.sstatic.net/URU8o.jpg)
>
> **Above:** Superposition of the half-power beam widths of the 13-element array of the Parkes 21-cm Mutlibeam Receiver, as used in [a study of a Fast Radio Bursters]<http://arxiv.org/abs/1602.07477>.

### Okay, now what you are asking about; "equivalent of CCD/CMOS sensors for non-optical wavelengths":

The first thing that comes to mind are bolometer and calorimeter chips. These are devices where the top layer absorbs photons, sometimes sensitive to a single photon, converting its energy to heat. The device directly below it in the same pixel is something very sensitive to tiny changes in temperature or a single thermal pulse, respectively.

For very low energy photons of microwave frequencies, there are transition-edge sensors like the ones used in the focal plane of the [South Pole Telescope](https://en.wikipedia.org/wiki/South_Pole_Telescope). For the newest focal plane array SPT-3G camera:

> The camera consists of over 16,000 detectors, split evenly between 90, 150, and 220 GHz.

For a good review of the underlying technology, start with:

* Wikipedia's [Transition-edge sensor](https://en.wikipedia.org/wiki/Transition-edge_sensor)
* MIT's Figueroa Group (Experimental Cosmology and Astrophysics Laboratory) [Transition Edge Sensors (TES)](http://web.mit.edu/figueroagroup/ucal/ucal_tes/)
* [South Pole Telescope Technical Publications](https://pole.uchicago.edu/public/Publications.html#h.u3a4w2pid6pe)

[![A single SPT-3G hexagonal detector wafer with flexible cables that connect the detectors to the rest of the readout chain. Each black spot on the wafer is an antenna that couples the incoming light to six different TES detectors (three bands and orthogonal polarizations) from Amy Bender's Github](https://i.sstatic.net/rKmdXm.jpg)](https://i.sstatic.net/rKmdX.jpg)

(click image for full size)

> A single SPT-3G hexagonal detector wafer with flexible cables that connect the detectors to the rest of the readout chain. Each black spot on the wafer is an antenna that couples the incoming light to six different TES detectors (three bands and orthogonal polarizations).

Source: Amy Bender's Github [SPT-3G](https://benderan.github.io/spt3g/spt3g.html)

From:

* J. A. Sobrin et al. (2022) [The Design and Integrated Performance of SPT-3G](https://arxiv.org/abs/2106.11202)

[![Figure 3. (Left) Picture of the SPT-3G detector array (consisting of ten detector modules) and supporting sub-kelvin architecture.](https://i.sstatic.net/WYGF8m.jpg)](https://i.sstatic.net/WYGF8.jpg) [![Figure 4. Scanning electron microscope micrograph of an SPT-3G pixel, showing the sinuous antenna at the center surrounded by six TES bolometers as well as various test structures.](https://i.sstatic.net/Cjv7Bm.jpg)](https://i.sstatic.net/Cjv7B.jpg)

(click images for full size)

> Figure 3. (Left) Picture of the SPT-3G detector array (consisting of ten detector modules) and supporting sub-kelvin architecture. The thermal stages are mechanically supported by a Graphlite truss structure that stands off the UC, IC, and 1K stages from a mounting ring at 4K. Each stage is machined from aluminum alloy 6061 and gold-plated to promote thermal conductivity across the components and between interfaces. The thermal stages are coupled to the sorption refrigerator using pressure-bonded annealed OFHC braided copper straps (Sobrin et al. 2018).

> Figure 4. Scanning electron microscope micrograph of an SPT-3G pixel, showing the sinuous antenna at the center surrounded by six TES bolometers as well as various test structures. The bolometers corresponding to one polarization state have been labeled with their respective observing bands.

---

This is from NASA's [Superconducting Detectors for Study of Infant Universe](https://www.nasa.gov/jpl/multimedia/superconducting-detectors-pia17993)

> The BICEP2 telescope at the South Pole uses novel technology developed at NASA's Jet Propulsion Laboratory in Pasadena, Calif. The focal plane shown here is an array of devices that use superconductivity to gather, filter, detect, and amplify polarized light from the cosmic microwave background -- relic radiation left over from the Big Bang that created our universe.
>
> The microscope is showing a close-up view of one of the 512 pixels on the focal plane, displayed on the screen in the background.
>
> Each pixel is made from a printed antenna that collects polarized millimeter-wavelength radiation, with a filter that selects the wavelengths to be detected. A sensitive detector is fabricated on a thin membrane created through a process called micro-machining.

Note that BICEP-3 and BICEP Array will supersede this technology, at least in total pixel count.

[![The BICEP2 telescope at the South Pole uses novel technology developed at NASA's Jet Propulsion Laboratory in Pasadena, Calif.  The focal plane shown here is an array of devices that use superconductivity to gather, filter, detect, and amplify polarized light from the cosmic microwave background](https://i.sstatic.net/pqcHWm.jpg)](https://i.sstatic.net/pqcHW.jpg)

(click for full size image)

See also

* [Design and Performance of the First BICEP Array Receiver](https://orca.cardiff.ac.uk/id/eprint/130169/1/2002.05228.pdf)

---

[@username_5's answer](https://astronomy.stackexchange.com/a/50743/7982) highlights the infrared telescope JWST's focal plane detectors.

See:

* Goddard Space Flight Center's JWST [Infrared Detectors](https://www.jwst.nasa.gov/content/about/innovations/infrared.html)

NIRCam, NIRSpec and FGS/NIRISS use mercury-cadmium-telluride (HgCdTe) semiconductor pixel arrays that convert lower energy infrared photons (here 0.6 yo 6 um) to carriers just like silicon sensors do, but they sit above a matching silicon CCD that accepts the charge produced in the low band gap material and do the necessary shifting for readout and transfer to the traditional charge amplifiers and ADCs.

MIRI however uses an arsenic-doped silicon array, based on impurity band conduction rather than the bulk silicon's conduction bands. G. H. Rieke et al. (2015) [The Mid-Infrared Instrument for the James Webb Space Telescope, VII: The MIRI Detectors](https://arxiv.org/abs/1508.02362) begins:

> The detectors of choice for the 5 - 28 µm range are arsenic-doped silicon impurity band conduction (Si:As IBC) devices. They have extensive space flight heritage, for example, arrays of these devices were used in all three Spitzer instruments (IRAC: Hora et al. (2004a); IRS: van Cleve et al. (1995), Houck et al. (2004); and MIPS: Gordon et al. (2004)), in WISE (Mainzer et al. 2008), in MSX (Mill et al. 1994) and in Akari (Onaka et al. 2007). The focal planes on these missions have demonstrated high detective quantum efficiencies, low dark current and relative freedom from other spurious signals, excellent photometric performance, and resistance to the effects of cosmic radiation. Similar detector arrays were selected for the Mid-Infrared Instrument (MIRI) on JWST.

[![Figure 1: A James Webb Space Telescope Near Infrared Camera (NIRCam) detector with optical baffles removed. Light is collected in the purple mercury-cadmium-telluride film. The film is pixelated, although the individual pixels are far too small to be seen by eye here. Credit: University of Arizona/NASA](https://i.sstatic.net/mnbTum.jpg)](https://i.sstatic.net/mnbTu.jpg)

(click image for full size)

> Figure 1: A James Webb Space Telescope Near Infrared Camera (NIRCam) detector with optical baffles removed. Light is collected in the purple mercury-cadmium-telluride film. The film is pixelated, although the individual pixels are far too small to be seen by eye here. Credit: University of Arizona/NASA

Source: Goddard Space Flight Center's JWST [Infrared Detectors](https://www.jwst.nasa.gov/content/about/innovations/infrared.html)

> **Comments:**
> **username_1**: NIRCam has nothing to do with radio astronomy. BICEP2 is a microwave experiment. The South Pole Telescope is mainly sub-mm.  
> **username_4**: @username_1 a continuum of technologies for a continuum of wavelengths.  

---

### Answer by username_5 on 2022-10-13. Score: 1

You could use an array of radio telescopes like a CCD, by pointing each dish at a different element of a sky grid, with each grid element as wide as the effective antenna beamwidth. I have never heard of an array being used in this way. Practically, I think interferometry is always used for radio telescope arrays, given the higher sensitivity and resolution possible.

As an example of other non-optical astronomy sensors, the JWST's NIRCam is "analogous to CCDs found in ordinary digital cameras" according to this [NASA website](https://www.jwst.nasa.gov/content/observatory/instruments/nircam.html).


---

