Laser Displacement Sensor

Started by Klaus Kragelund in sci.electronics.design7 years ago 31 replies

Hi We are investigating vibration frequencies on a PCB to avoid the components flying all over the place during vibration tetsting So, I...

Hi We are investigating vibration frequencies on a PCB to avoid the components flying all over the place during vibration tetsting So, I need to measure HF (up to 50kHz) displacement on a PCB with I guess better than 10um resolution. I have seen this one: http://www.keyence.eu/products/measure/laser-1d/index.jsp Anyone got experience with a good instrument for that (other than mount...


Laser Mouses might be used to predict/detect earthquakes (and ground movement).

Started by Skybuck Flying in sci.electronics.design7 years ago 27 replies

Hello, I have noticed many times by now that my laser mouse (logitech G3) is very sensitive. When the ground moves/shakes sometimes the...

Hello, I have noticed many times by now that my laser mouse (logitech G3) is very sensitive. When the ground moves/shakes sometimes the mouse will interrupt the screen saver. Today I also run one of my star trek online bots, and sikuli detected mouse movements which where recorded in a log file. It was very consistent and I don't think it was me. This constantion/observation th...


Butterfly package inductance

Started by Phil Hobbs in sci.electronics.design9 years ago 6 replies

Anybody round here got a number for the typical inductance of a butterfly-package laser mounted on a board with good lead dress? A friend of...

Anybody round here got a number for the typical inductance of a butterfly-package laser mounted on a board with good lead dress? A friend of mine is having trouble slowing his laser driver down below 500 ps, even with 10-ohm ferrite beads. Next thing to try is a cap after the beads, but some reasonable estimate would help. 20 nH or so, maybe? Thanks Phil Hobbs -- Dr Philip...


optical super-regen

Started by John Larkin in sci.electronics.design3 years ago 28 replies

Seems like you could make the optical equivalent of a super-regenerative radio receiver, with a laser. Like the super-regen, it would be very...

Seems like you could make the optical equivalent of a super-regenerative radio receiver, with a laser. Like the super-regen, it would be very sensitive but kinda noisy. I'm theorizing, based on just guessing, that a long-cavity laser, not a VCSEL, would work best. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechn...


coherence length

Started by George Herold in sci.electronics.design5 years ago 17 replies

A call today, someone wants to buy just a laser head. He said they liked our laser 'cause it had a long coherence length. I've never tried to...

A call today, someone wants to buy just a laser head. He said they liked our laser 'cause it had a long coherence length. I've never tried to measure it, but said it was related to the bandwidth. https://www.rp-photonics.com/coherence_length.html Which got me thinking at lunch. Do people measure the bandwidth by measuring the coherence length? (I picturing something like a Michels...


optical thing

Started by John Larkin in sci.electronics.design8 years ago 23 replies

We got a sample of a TO-can laser, red, in a flat-window package. Our fast photodetectors are all fiber optic, so the problem is to get some...

We got a sample of a TO-can laser, red, in a flat-window package. Our fast photodetectors are all fiber optic, so the problem is to get some of the light into the fiber so we can see the optical waveform. Sticking a fiber up against the laser window produced nothing measurable, as a little math will demonstrate. The area of a 9 micron single-mode fiber, or even a 60 micron multimode, is r...


integrated tof chip

Started by John Larkin in sci.electronics.design4 years ago 20 replies

http://www.st.com/en/imaging-and-photonics-solutions/proximity-sensors.html?querycriteria=produc tId=SC1934 This is amazing. A package about...

http://www.st.com/en/imaging-and-photonics-solutions/proximity-sensors.html?querycriteria=produc tId=SC1934 This is amazing. A package about the size of a 1206 resistor that has a vcsel laser, a photodiode, laser driver, and time-of-flight electronics. http://www.st.com/resource/en/datasheet/vl53l0x.pdf -- John Larkin Highland Technology, Inc picosecond timing precisio


Typical capacitance of a bigger laser diode?

Started by Joerg in sci.electronics.design10 years ago 41 replies

Folks, Looked through numerous datasheets in the 100-200mW power range from Sanyo, Sony, OSI, Ondax and so on ... nada. My experience when...

Folks, Looked through numerous datasheets in the 100-200mW power range from Sanyo, Sony, OSI, Ondax and so on ... nada. My experience when calling is that there is no further info available. So, does anyone know what the typical capacitance of an IR laser diode in that power range is? A SPICE model would be even better. Reason I ask is that we have to pulse-modulate the heck out of one, ...


new scanner thing

Started by John Larkin in sci.electronics.design9 years ago 14 replies

linked from Drudge...

linked from Drudge Report: http://washington.cbslocal.com/2012/07/11/new-homeland-security-laser-scanner-reads-people-at-mo lecular-level/ -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers an


Boosting bootstrap pin on sync buck

Started by Phil Hobbs in sci.electronics.design2 years ago 2 replies

So we got these nice little laser controller boards back from the assembler. (Super low noise, 150 mA drive, > 20 dB below the shot noise,...

So we got these nice little laser controller boards back from the assembler. (Super low noise, 150 mA drive, > 20 dB below the shot noise, digital control loops for constant laser power and temperature control. It uses the LPC845, a nice little Cortex M0+ that we're using more and more often. It runs at 30 MHz, and has both a single-cycle integer multiply and a microprogrammed integer


Frequency Detection Suggestions

Started by Bradley Kimbrough in sci.electronics.design5 years ago 12 replies

Hello All, I am currently building a stabilized Helium Neon laser that uses a 3 mode tube and stabilizes the optical frequency by monitoring a...

Hello All, I am currently building a stabilized Helium Neon laser that uses a 3 mode tube and stabilizes the optical frequency by monitoring a beat frequency between the modes. The beat frequency is 450-600 MHz and is sensed from the waste beam at the back of the laser tube. For a prototype I used an amplified moderately high speed Si detector that fed into a 12 bit 125 MSPS DAC. T


butterfly laser

Started by John Larkin in sci.electronics.design9 years ago 2 replies

Got this on ebay, milled the lid off to see what's...

Got this on ebay, milled the lid off to see what's inside. https://dl.dropbox.com/u/53724080/Lasers/Butterfly_ebay_2.JPG https://dl.dropbox.com/u/53724080/Lasers/Butterfly_ebay_Dyno1.jpg I haven't figured out the circuit with the inductor and, possibly, a parallel-plate capacitor. Bias tee? The laser and feedback photodiode are apparently sitting on a TE cooler and maybe a BeO in...


Awwkk, lasers invading your home

Started by Winfield Hill in sci.electronics.design2 years ago 15 replies

Laser-Based Audio Injection on Voice-Controllable...

Laser-Based Audio Injection on Voice-Controllable Systems https://it.slashdot.org/story/19/11/04/2054230/with-a-laser-researchers-say-they-can-hack-alexa- google-home-or-siri https://lightcommands.com/ https://lightcommands.com/20191104-Light-Commands.pdf Common 60mW lasers were sufficient for the task. -- Thanks, - Win


Frequency Detection Suggestions (corrected)

Started by Bradley Kimbrough in sci.electronics.design5 years ago 4 replies

Hello All, I am currently building a stabilized Helium Neon laser that uses a 3 mode tube and stabilizes the optical frequency by monitoring a...

Hello All, I am currently building a stabilized Helium Neon laser that uses a 3 mode tube and stabilizes the optical frequency by monitoring a beat frequency between the modes. The beat frequency is 450-600 kHz and is sensed from the waste beam at the back of the laser tube. For a prototype I used an amplified moderately high speed Si detector that fed into a 12 bit 125 MSPS DAC.


Calculating instantaneous Current through IGBT or SCR

Started by Anonymous in sci.electronics.design8 years ago 2 replies

Math is not my strong suit, and college was long, long ago. I have to select a IGBT or SCR to go into the power supply for a YAG laser.= The...

Math is not my strong suit, and college was long, long ago. I have to select a IGBT or SCR to go into the power supply for a YAG laser.= The network that powers the lamp is a LC circuit set up for critical damp= ing with a period of 250 uS. 250 uS is used because it corresponds to the = storage limit of the laser material. =20 A typical circuit might be 40 uH of series inductance, and...


Finding sufficiently crappy inductors

Started by Phil Hobbs in sci.electronics.design3 years ago 44 replies

Hi, all, I have a small laser/TEC controller board (2x3 inches). It uses a couple of fast switchers running off a 5V input rail: a...

Hi, all, I have a small laser/TEC controller board (2x3 inches). It uses a couple of fast switchers running off a 5V input rail: a TPS61175PWPR 3A boost making 13.5V for the laser controller and an LMR23630FDRRT 3A sync buck making 0.6-4.7V for the Class H TEC amplifier. The LMR part is the one with the 650-ps edges. A board-level shield and carefully-designed Faraday shield in the...


Side bands on diode laser (unexpected wavlength shift.)

Started by George Herold in sci.electronics.design9 years ago 4 replies

So I was putting ~100MHz sidebands on a diode laser (modulating the current.) to get a frequency 'measure' of the length of a...

So I was putting ~100MHz sidebands on a diode laser (modulating the current.) to get a frequency 'measure' of the length of a (~20cm) Fabry-Perot cavity (confocal). Wavlength ~780nm, FSR ~380 MHz, a source at 190 MHz would be perfect, but I don't have anything that high. So I cranked up the power with 95 MHz and got the second order sidebands at the frequency I wanted. (RF voltage of about...


narrow pulse generator

Started by Anonymous in sci.electronics.design7 months ago 8 replies

I want to make a narrow pulse. This will drive an e/o modulator to be an optical "fiducial" marker in a laser system. I can use a Leo Bodnar...

I want to make a narrow pulse. This will drive an e/o modulator to be an optical "fiducial" marker in a laser system. I can use a Leo Bodnar style laser driver chip to make a fast edge, but I don't know if the chip will propagate a 100 ps wide pulse. If it won't, maybe I can feed it a step and clip the output with a shorted transmission line. Making a 16.66 ohm line is a bit clumsy on ...


Commercial laser diodes

Started by George Herold in sci.electronics.design2 years ago 12 replies

Hi all, Searching for commercial laser diodes. wavlength ~600- 900 nm, power ~100mW, price

Hi all, Searching for commercial laser diodes. wavlength ~600- 900 nm, power ~100mW, price


Fastest rotating man-made object created (600 million RPM!)

Started by Jamie M in sci.electronics.design8 years ago 30 replies

Hi, A 4um diameter sphere of calcium carbonate was optically levitated by a laser, and the laser polarization was used to spin the sphere up...

Hi, A 4um diameter sphere of calcium carbonate was optically levitated by a laser, and the laser polarization was used to spin the sphere up to 600 million RPM, at which point it disintegrated! http://phys.org/news/2013-08-fastest-rotating-man-made.html I guess it won't be long until someone will do this with diamonds, as they are being optically levitated as well: http://phys.org/n...