The World's Tiniest Optical Gyroscope is Now Smaller Than a Grain of Rice
[Microelectromechanical sensors (MEMS)] are limited in their sensitivity, so engineers have also developed superior optical gyroscopes that perform with better accuracy and with the omission of moving parts. To do this these devices rely on a phenomenon referred to as the Sagnac effect.
Named after French physicist Georges Sagnac, this optical effect rooted in Einstein's theory of general relativity works by seeing the optical gyroscope split a beam of light into two and then rotate to manipulate the arrival of the now separate beams at its detector.
[...] Although very useful, so far even the best high-performance optical gyroscopes have been bigger than a golf ball and therefore incompatible with most of today's portable electronics. Previous attempts to build smaller versions of these high-precision devices, unfortunately, have always resulted in a reduced Sagnac effect signal and therefore reduced reliability and accuracy.
Now, a team of Caltech engineers led by Ali Hajimiri, Bren Professor of Electrical Engineering and Medical Engineering in the Division of Engineering and Applied Science, have found a way to shrink these devices while at the same time improving their accuracy. The discovery is bound to forever change the use of optical gyroscopes, likely making them even more popular and ever-present than MEMS. Caltech's novel optical gyroscope is 500 times smaller than the best devices currently available, making it smaller than a grain of rice, yet it can detect phase shifts 30 times smaller than even the most precise models out there. To do this, the tiny device uses something called "reciprocal sensitivity enhancement."
Also at Caltech.
Nanophotonic optical gyroscope with reciprocal sensitivity enhancement (DOI: 10.1038/s41566-018-0266-5) (DX) (correction)
(Score: 2) by fyngyrz on Tuesday October 30 2018, @06:24PM (7 children)
Not to go off on a tangent, but what's their angle here?
(Score: 2) by istartedi on Tuesday October 30 2018, @07:07PM (3 children)
I guess it's our turn to analyze the spin in this news.
Appended to the end of comments you post. Max: 120 chars.
(Score: 2) by fyngyrz on Wednesday October 31 2018, @12:45AM (2 children)
Turnabout is fair play, I hear. Depending on your orientation, of course.
(Score: 2) by mhajicek on Wednesday October 31 2018, @05:32AM (1 child)
Let's keep a level head about it.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 2) by VanessaE on Wednesday October 31 2018, @07:26PM
Well you know the usual story arc with new tech - the media will just dance around the issue of mass production, giving us all a ray of hope, until eventually the invention takes a straight line into someone's patent bin.
(ok, I'll just see myself out, now)
(Score: 0) by Anonymous Coward on Tuesday October 30 2018, @09:57PM (1 child)
Let us note that a ring laser gyroscope has no moving parts.
(Score: 0) by Anonymous Coward on Wednesday October 31 2018, @04:16PM
Well, the light is moving. :-)
(Score: 1) by Muad'Dave on Wednesday October 31 2018, @12:33PM
Sine on the dotted line and they might tell you. You may need a cosine-er, though.
(Score: 0) by Anonymous Coward on Tuesday October 30 2018, @06:39PM (3 children)
Seen Wolowitz back to space to install them on HUBBLE. Small, light and NO moving parts. a prefect fit for the myopic telescope with glasses.
(Score: 1, Insightful) by Anonymous Coward on Tuesday October 30 2018, @08:14PM (2 children)
The gyros in the Hubble are stabilizers. Optical gyros can't do that.
(Score: 0) by Anonymous Coward on Tuesday October 30 2018, @09:42PM (1 child)
And why not?
Movement is movement. If it detects movement then a counter force can be use of correct it.
If the Gyro on HUBBLE are just big dumb spinning flywheels, then call them that.
(Score: 1) by khallow on Wednesday October 31 2018, @02:05AM
And those gyroscopes were the way to do that - accurately and precisely.
(Score: 5, Interesting) by esperto123 on Tuesday October 30 2018, @06:48PM (2 children)
In my work I use fiber optic based gyros for heading measurement, these gyros are awesome, very compact and much better to maintain than the mechanical one, the "only" problem is that they cost about 3 times as much.
I assume that the 30 times more precise is compared to the previous miniature optic gyros, not the full size ones, but I could not find the actual figures. If the accuracy is on par with the full size ones, this thing will change inertial navigation field forever.
(Score: 0) by Anonymous Coward on Tuesday October 30 2018, @07:12PM
From the abstract: "The proof-of-concept device is capable of detecting phase shifts 30 times smaller than state-of-the-art miniature fibre-optic gyroscopes, despite being 500 times smaller in size" - yes, compared to minis not to navy balloons. Their techniques solve issues that larger units don't have, I think. (I can only get the abstract from here.)
(Score: 1, Insightful) by Anonymous Coward on Tuesday October 30 2018, @08:24PM
Testing my memory, weren't the first optical angular rate sensors called "ring laser gyros"? They were, iirc, briefcase sized and many thousands of $$$. Used to measure continental drift...?
(Score: 0) by Anonymous Coward on Tuesday October 30 2018, @07:22PM
"reciprocal sensitivity enhancement."
sounds kinky tbh
(Score: 1) by hereweareagain on Tuesday October 30 2018, @07:39PM (1 child)
Would be interesting to see what they could do with say, motorcycle applications...
--I'm willing to admit I just *might* be wrong... Are you?
(Score: 0) by Anonymous Coward on Tuesday October 30 2018, @08:30PM
> I'm willing to admit I just *might* be wrong... Are you?
Absolutely, after writing a couple of engineering reference/text books and then getting feedback on typos and more serious errors, I'm perfectly happy to admit that I'm wrong. I usually go back to our final draft, to make sure the error wasn't created by our editor (have seen this a few times). It's a good ego busting experience, recommended to anyone.
(Score: 1) by anubi on Tuesday October 30 2018, @09:05PM (4 children)
Who cares much about the "size" of the loop? The inside of the loop is usable for other things. I don't think it even has to be circular. I believe all that counts is that the loop opening is planar, and even if it isn't, you will just get sensitivity to any other planes in the geometry you used.
The emitter and sensor can be made very small and tucked out of the way.
Won't everything that is not a rotation present itself to the sensor as no differential delay, hence unseen?
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 1) by anubi on Tuesday October 30 2018, @09:14PM (3 children)
Oh yes...size of the opening will determine the wavelengths per radian.
(I am posting from a phone at DelTaco, as I no longer have internet at my house... My posts have to be far fewer and brief, and often incomplete ).
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 0) by Anonymous Coward on Wednesday October 31 2018, @12:38PM (2 children)
> I no longer have internet at my house
Is this by choice, or did someone/something take away your home access? I like your long posts about "appropriate tech" (like the older diesel van), hope they return.
(Score: 0) by Anonymous Coward on Thursday November 01 2018, @04:53AM (1 child)
I was getting internet access through my employer, but he got really fed up with California, packed up and moved the whole shebang to Colorado.
I cannot see me paying the kind of fees the companies ask. Especially mandating bundling with things I flat do not want.
(Score: 2) by takyon on Thursday November 01 2018, @05:12AM
It's amazing how some ISPs will charge you the same or more for plain Internet service as they will for a bundle including that same Internet service, cable TV, and phone service.
Starlink [arstechnica.com] can't come fast enough.
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