Lasers
Category archives for Lasers
Poll: Top Physics Story of 2010?
Posted by Chad Orzel on December 28, 2010 It’s the last week of the (calendar) year, which means it’s a good time to recap the previous twelve months worth of scientific news. Typically, publications like Physics World will publish a list of top ten physics stories of 2010, but we’re all Web 2.0 these days, so it seems more appropriate to put this…
Dance of the Photons by Anton Zeilinger
Posted by Chad Orzel on December 1, 2010 I hadn’t heard anything about Dance of the Photons: From Einstein to Quantum Teleportation before it turned up in my mailbox, courtesy of some kind publicist at Farrar, Straus, and Giroux, otherwise I would’ve been eagerly anticipating it. Anton Zeilinger is a name to conjure with in quantum optics, having built an impressive career out…
Interference of Independent Photon Beams: The Pfleegor-Mandel Experiment
Posted by Chad Orzel on November 19, 2010 Earlier this week, I talked about the technical requirements for taking a picture of an interference pattern from two independent lasers, and mentioned in passing that a 1967 experiment by Pfleegor and Mandel had already shown the interference effect. Their experiment was clever enough to deserve the ResearchBlogging Q&A treatment, though, so here we go:…
How Do You See Interference Between Independent Lasers?
Posted by Chad Orzel on November 15, 2010 This is adapted from an answer to a question at the Physics Stack Exchange site. The questioner asked: It seems that if the coherence length of a laser is big enough, it is possible to observe a (moving) interference picture by combining them. Is it true? How fast should photo-detectors be for observing of the…
The ABC’s of AMO Physics
Posted by Chad Orzel on September 3, 2010 Over at Confused at a Higher Level, Melissa offers an alphabetical list of essential supplies for a condensed matter experimentalist at a small college. This is a fun idea for back-to-school time, so I’ll steal it, and offer the following alphabetical list of essentials for Atomic, Molecular, and Optical physics at a small college, kind…
Bunches and Antibunches of Atoms: Hanbury Brown and Twiss Effects in Ultracold Atoms
Posted by Chad Orzel on August 24, 2010 Two papers in one post this time out. One of these was brought to my attention by Joerg Heber, the other I was reminded of when checking some information for last week’s mathematical post on photons. They fit extremely well together though, and both relate to the photon correlation stuff I was talking about last…
Quantum Optics from the Opposite Direction: QED Limits on Laser Intensities
Posted by Chad Orzel on August 18, 2010 Most of the time, when we talk about seeing quantum effects from light, we talk about extremely weak beams– looking at intensities where one photon more or less represents a significant change in the intensity of the light. Last week, though, Physics Buzz wrote up a paper that goes in the other direction: they suggest…
Do Not Look In Laser Pointer With Remaining Eye
Posted by Chad Orzel on August 13, 2010 Some folks I used to work with at NIST have looked at cheap green laser pointers, and found a potential danger. Some of the dimmer-looking green lasers are not so dim in the infrared, and in one case emitted 10X the rated power in invisible light. This could be a potential eye hazard. You can…
What Do You Need to Make Cold Atoms? Part 2: Lasers and Optics
Posted by Chad Orzel on August 12, 2010 Following on yesterday’s discussion of the vacuum hardware needed for cooling atoms, let’s talk about the other main component of the apparatus: the optical system. The primary technique used for making cold atoms is laser cooling, and I’m sure it will come as no surprise that this requires lasers, and where there are lasers, there…
Protons: Even Smaller Than We Thought
Posted by Chad Orzel on July 9, 2010 The big physics story at the moment is probably the new measurement of the size of the proton, which is reported in this Nature paper (which does not seem to be on the arxiv, alas). This is kind of a hybrid of nuclear and atomic physics, as it’s a spectroscopic measurement of a quasi-atom involving…
