They are pretty awesome. Once got some data that seemed to be bad out of one and realized that the entire error was exactly accounted for by the Coriolis effect from the rotation of the earth.
I believe that the tech you mention is the same tech as used by the flat-earthers in Behind The Curve in the $20k gyroscope they bought, to try and prove that the Earth did not rotate (except they found it picked up a 15-degree-per-hour drift, debunking themselves, so then doubted the technology, heh) [1].
But, aside from the laser/fibre-optic tech, there are also MEMS [2] gyroscopes also — which is almost nanotech IMO — which are used as sensors in modern phones/tablets, and also on drones (to assist with navigation), plus various other robotics uses, and more.
MEMS gyros — often with an accelerometer (aka IMU / inertial measurement unit) and maybe a magnetometer (compass) — can be bought from folk such as Adafruit [3], SparkFun, etc. (I've got a few different ones myself), and hooked up to e.g. an Arduino or similar MCU (or indeed anything else that speaks can speak the appropriate protocol, e.g. I2C/SPI/etc depending on the board in question).
Hmm, just looked for a good image of how a MEMS gyro works, and didn't come up with what I was looking for / recall seeing before (I'm a bit pushed for time), but there's a diagram on this WP page [4].
I've done some projects myself with MPU6050 and some with its 9-axis "bigger brother" the MPU9250 (same as 6050, but with added 3-axis magnetometer/compass). I've also used the LSM9DS1 — another 9-axis IMU, just a different chip.
— Yeah, definitely amazing tech for the price. Cheap as chips! /me gets coat.
Ingenuity, the Mars helicopter/drone, apparently includes a bunch of off-the-shelf kit like this — IIRC I think a bunch of the parts are made by SparkFun. I don't recall any specifics though.
