While the frequencies are a tad too high for anything currently
discussed on SED, the principle is familiar.

The following are likely behind a paywall, but all major libraries
carry Science. And drafts of the articles may be findable.

"Room-temperature mid-infrared detector", REUVEN GORDON, SCIENCE • 2
Dec 2021 • Vol 374, Issue 6572 • pp. 1201-1202 • DOI:
10.1126/science.abm4252. This is the summary, and points to the two
articles discussed, which are in the 3 Dec '21 issue of Science
Magazine.

"Continuous-wave frequency upconversion with a molecular
optomechanical nanocavity", Continuous-wave frequency upconversion
with a molecular optomechanical nanocavity", WEN CHENPHILIPPE ROELLI
et al, SCIENCE • 2 Dec 2021 • Vol 374, Issue 6572 • pp. 1264-1267 •
DOI: 10.1126/science.abk3106.

The basic scheme is a single gold nanosphere (the ball) resting on one
(flat) two (V-grooves) gold surfaces, with a monolayer of
Biphenyl-4-thiol molecules in between ball and surface at the contact
point or points. The Biphenyl-4-thiol molecules act as a parametric
converter, allowing a near-IR pump beam to upconvert a Mid-IR signal
up to visible, where it is easily detected.

As I understand it, in this parametric converter, no electron current
flows. This is not a diode.

Case 1: The signal is at 32 THz (9.3 micron). The pump is far
higher.The output is around 437 THz.

Case 2: MIR is 8.5 to 15 microns, from a Quantum Cascade laser. The
pump is 785 nm, with a Acousto-Optical Modulator.

I don't fully understand the mechanism, but they talk of Stokes and
Anti-Stokes sidebands, which sounds like a big clue. A form of
four-wave mixing?

Joe Gwinn

Joe Gwinn wrote:
> While the frequencies are a tad too high for anything currently
> discussed on SED, the principle is familiar.
>
> The following are likely behind a paywall, but all major libraries
> carry Science. And drafts of the articles may be findable.
>
> "Room-temperature mid-infrared detector", REUVEN GORDON, SCIENCE • 2
> Dec 2021 • Vol 374, Issue 6572 • pp. 1201-1202 • DOI:
> 10.1126/science.abm4252. This is the summary, and points to the two
> articles discussed, which are in the 3 Dec '21 issue of Science
> Magazine.
>
> "Continuous-wave frequency upconversion with a molecular
> optomechanical nanocavity", Continuous-wave frequency upconversion
> with a molecular optomechanical nanocavity", WEN CHENPHILIPPE ROELLI
> et al, SCIENCE • 2 Dec 2021 • Vol 374, Issue 6572 • pp. 1264-1267 •
> DOI: 10.1126/science.abk3106.
>
> The basic scheme is a single gold nanosphere (the ball) resting on one
> (flat) two (V-grooves) gold surfaces, with a monolayer of
> Biphenyl-4-thiol molecules in between ball and surface at the contact
> point or points. The Biphenyl-4-thiol molecules act as a parametric
> converter, allowing a near-IR pump beam to upconvert a Mid-IR signal
> up to visible, where it is easily detected.
>
> As I understand it, in this parametric converter, no electron current
> flows. This is not a diode.
>
> Case 1: The signal is at 32 THz (9.3 micron). The pump is far
> higher.The output is around 437 THz.
>
> Case 2: MIR is 8.5 to 15 microns, from a Quantum Cascade laser. The
> pump is 785 nm, with a Acousto-Optical Modulator.
>
> I don't fully understand the mechanism, but they talk of Stokes and
> Anti-Stokes sidebands, which sounds like a big clue. A form of
> four-wave mixing?
>
> Joe Gwinn
>

There are lots of resonator-enhanced nonlinear optics things.
Room-temperature mid-IR detectors are mostly crappy (HgCdTe and
suchlike), so a better one is welcome.

This one is going to be a bit of a schlepp to get working at any
reasonable efficiency over any reasonable detection area, but who
knows--somebody might figure out a way to scale it.

Cheers

Phil

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Wed, 29 Dec 2021 15:40:55 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>Joe Gwinn wrote:
>> While the frequencies are a tad too high for anything currently
>> discussed on SED, the principle is familiar.
>>
>> The following are likely behind a paywall, but all major libraries
>> carry Science. And drafts of the articles may be findable.
>>
>> "Room-temperature mid-infrared detector", REUVEN GORDON, SCIENCE • 2
>> Dec 2021 • Vol 374, Issue 6572 • pp. 1201-1202 • DOI:
>> 10.1126/science.abm4252. This is the summary, and points to the two
>> articles discussed, which are in the 3 Dec '21 issue of Science
>> Magazine.
>>
>> "Continuous-wave frequency upconversion with a molecular
>> optomechanical nanocavity", Continuous-wave frequency upconversion
>> with a molecular optomechanical nanocavity", WEN CHENPHILIPPE ROELLI
>> et al, SCIENCE • 2 Dec 2021 • Vol 374, Issue 6572 • pp. 1264-1267 •
>> DOI: 10.1126/science.abk3106.
>>
>> The basic scheme is a single gold nanosphere (the ball) resting on one
>> (flat) two (V-grooves) gold surfaces, with a monolayer of
>> Biphenyl-4-thiol molecules in between ball and surface at the contact
>> point or points. The Biphenyl-4-thiol molecules act as a parametric
>> converter, allowing a near-IR pump beam to upconvert a Mid-IR signal
>> up to visible, where it is easily detected.
>>
>> As I understand it, in this parametric converter, no electron current
>> flows. This is not a diode.
>>
>> Case 1: The signal is at 32 THz (9.3 micron). The pump is far
>> higher.The output is around 437 THz.
>>
>> Case 2: MIR is 8.5 to 15 microns, from a Quantum Cascade laser. The
>> pump is 785 nm, with a Acousto-Optical Modulator.
>>
>> I don't fully understand the mechanism, but they talk of Stokes and
>> Anti-Stokes sidebands, which sounds like a big clue. A form of
>> four-wave mixing?
>>
>> Joe Gwinn
>>
>
>There are lots of resonator-enhanced nonlinear optics things.
>Room-temperature mid-IR detectors are mostly crappy (HgCdTe and
>suchlike), so a better one is welcome.
>
>This one is going to be a bit of a schlepp to get working at any
>reasonable efficiency over any reasonable detection area, but who
>knows--somebody might figure out a way to scale it.

I'm betting that the Astronomers will be pretty interested. Opens up
a new EM window; never know what you'll find.

As for the underlying mechanism, are there any tutorial articles you
could suggest?

Thanks,

Joe Gwinn

Joe Gwinn wrote:
> On Wed, 29 Dec 2021 15:40:55 -0500, Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>> Joe Gwinn wrote:
>>> While the frequencies are a tad too high for anything currently
>>> discussed on SED, the principle is familiar.
>>>
>>> The following are likely behind a paywall, but all major libraries
>>> carry Science. And drafts of the articles may be findable.
>>>
>>> "Room-temperature mid-infrared detector", REUVEN GORDON, SCIENCE • 2
>>> Dec 2021 • Vol 374, Issue 6572 • pp. 1201-1202 • DOI:
>>> 10.1126/science.abm4252. This is the summary, and points to the two
>>> articles discussed, which are in the 3 Dec '21 issue of Science
>>> Magazine.
>>>
>>> "Continuous-wave frequency upconversion with a molecular
>>> optomechanical nanocavity", Continuous-wave frequency upconversion
>>> with a molecular optomechanical nanocavity", WEN CHENPHILIPPE ROELLI
>>> et al, SCIENCE • 2 Dec 2021 • Vol 374, Issue 6572 • pp. 1264-1267 •
>>> DOI: 10.1126/science.abk3106.
>>>
>>> The basic scheme is a single gold nanosphere (the ball) resting on one
>>> (flat) two (V-grooves) gold surfaces, with a monolayer of
>>> Biphenyl-4-thiol molecules in between ball and surface at the contact
>>> point or points. The Biphenyl-4-thiol molecules act as a parametric
>>> converter, allowing a near-IR pump beam to upconvert a Mid-IR signal
>>> up to visible, where it is easily detected.
>>>
>>> As I understand it, in this parametric converter, no electron current
>>> flows. This is not a diode.
>>>
>>> Case 1: The signal is at 32 THz (9.3 micron). The pump is far
>>> higher.The output is around 437 THz.
>>>
>>> Case 2: MIR is 8.5 to 15 microns, from a Quantum Cascade laser. The
>>> pump is 785 nm, with a Acousto-Optical Modulator.
>>>
>>> I don't fully understand the mechanism, but they talk of Stokes and
>>> Anti-Stokes sidebands, which sounds like a big clue. A form of
>>> four-wave mixing?
>>>
>>> Joe Gwinn
>>>
>>
>> There are lots of resonator-enhanced nonlinear optics things.
>> Room-temperature mid-IR detectors are mostly crappy (HgCdTe and
>> suchlike), so a better one is welcome.
>>
>> This one is going to be a bit of a schlepp to get working at any
>> reasonable efficiency over any reasonable detection area, but who
>> knows--somebody might figure out a way to scale it.
>
> I'm betting that the Astronomers will be pretty interested. Opens up
> a new EM window; never know what you'll find.

Nah, astronomers can afford cryogenically-cooled detectors. HgCdTe
arrays are fairly heartbreaking, but at least you get many pixels, and a
given pixel can have any etendue you like.

A single resonator gets you at most one optical mode, i.e. an etendue of
lambda**2/2 per polarization. With thermal light, the mode volume is
only very sparsely filled, so that's not a lot of photons per second.

>
> As for the underlying mechanism, are there any tutorial articles you
> could suggest?

I'm actually not a big nonlinear optics guy--I took one course on it in
grad school, and have never built a parametric converter or optical
harmonic generator. I used to have one (or at least IBM bought one for
me), but I haven't gone through the math in 35 years or so.

From a phenomenological POV, the magic-goo guys give you this nice
material with some nice large second- and third-order dielectric
susceptibilities. (For a solid, these are both tensors.)

For given incident E fields, you use the susceptibilities to calculate
the nonlinear dielectric polarization, and apply the Helmholtz
propagator to figure out what the output power will be for the given
geometry. (I forget exactly how that part of the calculation goes, but
it isn't super complicated IIRC.)

Then you moan about how tiny the output power is, and look for ways to
make it bigger. With a crystal, you can sometimes find a geometry and
a choice of incident k vectors so that the nonlinear polarization
phase-matches to a propagating wave.

At that point, the output signal builds up and builds up with distance,
so you can sometimes make a pretty efficient frequency converter. (For
parametric converters, "pretty efficient" is a few percent in general.)

For a resonator, you probably have to use FDTD to calculate the output,
though you can certainly do some decent first-order estimates
analytically. It'll look like a single dipole absorber, and probably a
single dipole emitter as well. (That's a clue that the efficiency is
going to be poor when the input and output wavelengths are very different.)

Fun stuff. I'd like a chance to build a parametric converter one of
these times, but it's well below making ECDLs on the priority list.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Wed, 29 Dec 2021 17:15:16 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>Joe Gwinn wrote:
>> On Wed, 29 Dec 2021 15:40:55 -0500, Phil Hobbs
>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>
>>> Joe Gwinn wrote:
>>>> While the frequencies are a tad too high for anything currently
>>>> discussed on SED, the principle is familiar.
>>>>
>>>> The following are likely behind a paywall, but all major libraries
>>>> carry Science. And drafts of the articles may be findable.
>>>>
>>>> "Room-temperature mid-infrared detector", REUVEN GORDON, SCIENCE • 2
>>>> Dec 2021 • Vol 374, Issue 6572 • pp. 1201-1202 • DOI:
>>>> 10.1126/science.abm4252. This is the summary, and points to the two
>>>> articles discussed, which are in the 3 Dec '21 issue of Science
>>>> Magazine.
>>>>
>>>> "Continuous-wave frequency upconversion with a molecular
>>>> optomechanical nanocavity", Continuous-wave frequency upconversion
>>>> with a molecular optomechanical nanocavity", WEN CHENPHILIPPE ROELLI
>>>> et al, SCIENCE • 2 Dec 2021 • Vol 374, Issue 6572 • pp. 1264-1267 •
>>>> DOI: 10.1126/science.abk3106.
>>>>
>>>> The basic scheme is a single gold nanosphere (the ball) resting on one
>>>> (flat) two (V-grooves) gold surfaces, with a monolayer of
>>>> Biphenyl-4-thiol molecules in between ball and surface at the contact
>>>> point or points. The Biphenyl-4-thiol molecules act as a parametric
>>>> converter, allowing a near-IR pump beam to upconvert a Mid-IR signal
>>>> up to visible, where it is easily detected.
>>>>
>>>> As I understand it, in this parametric converter, no electron current
>>>> flows. This is not a diode.
>>>>
>>>> Case 1: The signal is at 32 THz (9.3 micron). The pump is far
>>>> higher.The output is around 437 THz.
>>>>
>>>> Case 2: MIR is 8.5 to 15 microns, from a Quantum Cascade laser. The
>>>> pump is 785 nm, with a Acousto-Optical Modulator.
>>>>
>>>> I don't fully understand the mechanism, but they talk of Stokes and
>>>> Anti-Stokes sidebands, which sounds like a big clue. A form of
>>>> four-wave mixing?
>>>>
>>>> Joe Gwinn
>>>>
>>>
>>> There are lots of resonator-enhanced nonlinear optics things.
>>> Room-temperature mid-IR detectors are mostly crappy (HgCdTe and
>>> suchlike), so a better one is welcome.
>>>
>>> This one is going to be a bit of a schlepp to get working at any
>>> reasonable efficiency over any reasonable detection area, but who
>>> knows--somebody might figure out a way to scale it.
>>
>> I'm betting that the Astronomers will be pretty interested. Opens up
>> a new EM window; never know what you'll find.
>
>Nah, astronomers can afford cryogenically-cooled detectors. HgCdTe
>arrays are fairly heartbreaking, but at least you get many pixels, and a
>given pixel can have any etendue you like.
>
>A single resonator gets you at most one optical mode, i.e. an etendue of
>lambda**2/2 per polarization. With thermal light, the mode volume is
>only very sparsely filled, so that's not a lot of photons per second.
>
>>
>> As for the underlying mechanism, are there any tutorial articles you
>> could suggest?
>
>I'm actually not a big nonlinear optics guy--I took one course on it in
>grad school, and have never built a parametric converter or optical
>harmonic generator. I used to have one (or at least IBM bought one for
>me), but I haven't gone through the math in 35 years or so.
>
> From a phenomenological POV, the magic-goo guys give you this nice
>material with some nice large second- and third-order dielectric
>susceptibilities. (For a solid, these are both tensors.)
>
>For given incident E fields, you use the susceptibilities to calculate
>the nonlinear dielectric polarization, and apply the Helmholtz
>propagator to figure out what the output power will be for the given
>geometry. (I forget exactly how that part of the calculation goes, but
>it isn't super complicated IIRC.)
>
>Then you moan about how tiny the output power is, and look for ways to
>make it bigger. With a crystal, you can sometimes find a geometry and
>a choice of incident k vectors so that the nonlinear polarization
>phase-matches to a propagating wave.
>
>At that point, the output signal builds up and builds up with distance,
>so you can sometimes make a pretty efficient frequency converter. (For
>parametric converters, "pretty efficient" is a few percent in general.)
>
>For a resonator, you probably have to use FDTD to calculate the output,
>though you can certainly do some decent first-order estimates
>analytically. It'll look like a single dipole absorber, and probably a
>single dipole emitter as well. (That's a clue that the efficiency is
>going to be poor when the input and output wavelengths are very different.)
>
>Fun stuff. I'd like a chance to build a parametric converter one of
>these times, but it's well below making ECDLs on the priority list.

Ahh. Way more complicated than I realized.

Maybe the THz imaging folk then. Or just bored physicists.

Joe Gwinn

Joe Gwinn wrote:
> On Wed, 29 Dec 2021 17:15:16 -0500, Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>> Joe Gwinn wrote:
>>> On Wed, 29 Dec 2021 15:40:55 -0500, Phil Hobbs
>>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>>
>>>> Joe Gwinn wrote:
>>>>> While the frequencies are a tad too high for anything currently
>>>>> discussed on SED, the principle is familiar.
>>>>>
>>>>> The following are likely behind a paywall, but all major libraries
>>>>> carry Science. And drafts of the articles may be findable.
>>>>>
>>>>> "Room-temperature mid-infrared detector", REUVEN GORDON, SCIENCE • 2
>>>>> Dec 2021 • Vol 374, Issue 6572 • pp. 1201-1202 • DOI:
>>>>> 10.1126/science.abm4252. This is the summary, and points to the two
>>>>> articles discussed, which are in the 3 Dec '21 issue of Science
>>>>> Magazine.
>>>>>
>>>>> "Continuous-wave frequency upconversion with a molecular
>>>>> optomechanical nanocavity", Continuous-wave frequency upconversion
>>>>> with a molecular optomechanical nanocavity", WEN CHENPHILIPPE ROELLI
>>>>> et al, SCIENCE • 2 Dec 2021 • Vol 374, Issue 6572 • pp. 1264-1267 •
>>>>> DOI: 10.1126/science.abk3106.
>>>>>
>>>>> The basic scheme is a single gold nanosphere (the ball) resting on one
>>>>> (flat) two (V-grooves) gold surfaces, with a monolayer of
>>>>> Biphenyl-4-thiol molecules in between ball and surface at the contact
>>>>> point or points. The Biphenyl-4-thiol molecules act as a parametric
>>>>> converter, allowing a near-IR pump beam to upconvert a Mid-IR signal
>>>>> up to visible, where it is easily detected.
>>>>>
>>>>> As I understand it, in this parametric converter, no electron current
>>>>> flows. This is not a diode.
>>>>>
>>>>> Case 1: The signal is at 32 THz (9.3 micron). The pump is far
>>>>> higher.The output is around 437 THz.
>>>>>
>>>>> Case 2: MIR is 8.5 to 15 microns, from a Quantum Cascade laser. The
>>>>> pump is 785 nm, with a Acousto-Optical Modulator.
>>>>>
>>>>> I don't fully understand the mechanism, but they talk of Stokes and
>>>>> Anti-Stokes sidebands, which sounds like a big clue. A form of
>>>>> four-wave mixing?
>>>>>
>>>>> Joe Gwinn
>>>>>
>>>>
>>>> There are lots of resonator-enhanced nonlinear optics things.
>>>> Room-temperature mid-IR detectors are mostly crappy (HgCdTe and
>>>> suchlike), so a better one is welcome.
>>>>
>>>> This one is going to be a bit of a schlepp to get working at any
>>>> reasonable efficiency over any reasonable detection area, but who
>>>> knows--somebody might figure out a way to scale it.
>>>
>>> I'm betting that the Astronomers will be pretty interested. Opens up
>>> a new EM window; never know what you'll find.
>>
>> Nah, astronomers can afford cryogenically-cooled detectors. HgCdTe
>> arrays are fairly heartbreaking, but at least you get many pixels, and a
>> given pixel can have any etendue you like.
>>
>> A single resonator gets you at most one optical mode, i.e. an etendue of
>> lambda**2/2 per polarization. With thermal light, the mode volume is
>> only very sparsely filled, so that's not a lot of photons per second.
>>
>>>
>>> As for the underlying mechanism, are there any tutorial articles you
>>> could suggest?
>>
>> I'm actually not a big nonlinear optics guy--I took one course on it in
>> grad school, and have never built a parametric converter or optical
>> harmonic generator. I used to have one (or at least IBM bought one for
>> me), but I haven't gone through the math in 35 years or so.
>>
>> From a phenomenological POV, the magic-goo guys give you this nice
>> material with some nice large second- and third-order dielectric
>> susceptibilities. (For a solid, these are both tensors.)
>>
>> For given incident E fields, you use the susceptibilities to calculate
>> the nonlinear dielectric polarization, and apply the Helmholtz
>> propagator to figure out what the output power will be for the given
>> geometry. (I forget exactly how that part of the calculation goes, but
>> it isn't super complicated IIRC.)
>>
>> Then you moan about how tiny the output power is, and look for ways to
>> make it bigger. With a crystal, you can sometimes find a geometry and
>> a choice of incident k vectors so that the nonlinear polarization
>> phase-matches to a propagating wave.
>>
>> At that point, the output signal builds up and builds up with distance,
>> so you can sometimes make a pretty efficient frequency converter. (For
>> parametric converters, "pretty efficient" is a few percent in general.)
>>
>> For a resonator, you probably have to use FDTD to calculate the output,
>> though you can certainly do some decent first-order estimates
>> analytically. It'll look like a single dipole absorber, and probably a
>> single dipole emitter as well. (That's a clue that the efficiency is
>> going to be poor when the input and output wavelengths are very different.)
>>
>> Fun stuff. I'd like a chance to build a parametric converter one of
>> these times, but it's well below making ECDLs on the priority list.
>
> Ahh. Way more complicated than I realized.
>
> Maybe the THz imaging folk then. Or just bored physicists.
>
> Joe Gwinn
>

It's worth trying this sort of stuff out--new technologies typically
don't appear overnight. However, for it to be more than a pretext for
writing papers and dissertations, you have to think fairly deeply about
how to scale it to technologically-useful levels of efficiency and cost.

Coming up with a new scheme that looks like it could scale well is very
exciting.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com