The telescopes of the future

Caltech has demonstrated a camera without lenses.

https://petapixel.com/2017/06/22/cal...camera-future/

quote
The camera has an arsenal of light receivers, each of which can
individually add a tightly controlled time delay to the light it
receives, allowing you to 'look' in different directions and focus on
different things in the scene in-front of the chip.

"We've created a single thin layer of integrated silicon photonics that
emulates the lens and sensor of a digital camera, reducing the thickness
and cost of digital cameras," says Ali Hajimiri, the leader of the team
looking into the camera. "It can mimic a regular lens, but can switch
from a fish-eye to a telephoto lens instantaneously -- with just a simple
adjustment in the way the array receives light."

The researchers at Caltech also think that the camera might have
implications for space photography. They envisage huge, flat telescopes
in Space or on the ground capable of imaging our universe.
end quote

Ground based huge telescopes are possible at an extreme low cost, since
the lenses are actually the most expensive part of the whole telescope.

Pointing is instantaneous, no wait to move heavy lenses. And since there
are no lenses, telescope can be made of huge dimensions, with much more
collecting power than what we can ever obtain with lenses.

The telescopes of the future may be just a sensitive wall of electronics.

[Mod. note: non-ASCII characters removed, please don't post non-ASCII
characters. It has been a long time since any professional telescope
had a large lens, nor do I think it's the case any more that the
optics are the most expensive part of the instrument -- mjh]

Le 30/07/2017 Ã* 10:57, jacobnavia a écrit :
It has been a long time since any professional telescope
had a large lens, nor do I think it's the case any more that the
optics are the most expensive part of the instrument -- mjh

OK, now we use mirrors, I should have been more precise.

But the mirrors, and the associated machinery for moving them, is quite
a BIG part of any modern telescope budget...

On 7/30/2017 10:57 AM, jacobnavia wrote:
Caltech has demonstrated a camera without lenses.

https://petapixel.com/2017/06/22/cal...camera-future/

Unfortunately the link (and the links referenced in it) do not
give much information. Interesting questions a

1) Sensitivity (signal to noise ratio) compared to a camera
that does have a lens (and e.g. a CCD as detector)?
2) Does 'optical' mean infra-red or visible light? (IR may
be much more easy).
3) What is the bandwidth? A heterodyne system might be quite
limited here (which of course turns into an advantage if
you want a single spectral line..)

I don't immediately see this kind of information in related
articles either:
http://ieeexplore.ieee.org/search/searchresult.jsp?queryText=optical%20phased%20arra y

--
Jos

Le 31/07/2017 Ã* 23:06, Jos Bergervoet a écrit :
On 7/30/2017 10:57 AM, jacobnavia wrote:
Caltech has demonstrated a camera without lenses.

https://petapixel.com/2017/06/22/cal...camera-future/

Unfortunately the link (and the links referenced in it) do not
give much information. Interesting questions a

Maybe you have an explanation on how it works?

Or a link to an introductory article on optical phased arrays?

Thanks

On 31/07/2017 22:06, Jos Bergervoet wrote:
On 7/30/2017 10:57 AM, jacobnavia wrote:
Caltech has demonstrated a camera without lenses.

https://petapixel.com/2017/06/22/cal...camera-future/

Unfortunately the link (and the links referenced in it) do not
give much information. Interesting questions a

1) Sensitivity (signal to noise ratio) compared to a camera
that does have a lens (and e.g. a CCD as detector)?

My guess is rather limited. A bit more is online he

http://www.caltech.edu/news/ultra-th...t-lenses-78731

It is an 8x8 heterodyne OPA array - article behind a paywall

http://authors.library.caltech.edu/78652/
https://www.osapublishing.org/viewme...7-JW2A.9&seq=0

Academic users should have access though. Resolution stated as 0.75
degrees and beam steering of 8 degrees.

2) Does 'optical' mean infra-red or visible light? (IR may
be much more easy).
3) What is the bandwidth? A heterodyne system might be quite
limited here (which of course turns into an advantage if
you want a single spectral line..)

I don't immediately see this kind of information in related
articles either:
http://ieeexplore.ieee.org/search/searchresult.jsp?queryText=optical%20phased%20arra y

It might be handy for playing hunt the transient GRB optical component.
(though I suspect widefield survey cameras would win handsomely)

--
Regards,
Martin Brown