Last time, I showed you how you could construct a photon, a light particle, in a configuration of mirrors called a ring cavity. This time I’ll show you that sometimes, you can’t make just one particle—they only come in pairs. And sometimes, the notion of a particle doesn’t make any sense at all. (This post relies heavily on last week’s post, so if you haven’t read that, I recommend you do so.) Disclaimer: What I’m about to describe is only the simplest case, and I make simplifications for the sake of exposition. It is possible to capture and manipulate
metrology
Condensed Matter / optics / Physics / etc.
The Graphene Electro-Optic Modulator
Say we have a beam of light—maybe we made it with a laser. We’d like be able to change the intensity of the beam so that we can alternately brighten and dim it. Moreover, we’d like to be able to do so quickly. Physically blocking and unblocking the beam just isn’t fast enough. So what do we do? The solution is to make an electric switch so we can change how the light behaves via electrical signals. This is an electro-optic modulator (EOM). Two weeks ago, I introduced graphene to you all. And last week, I described some of
Condensed Matter / optics / Physics / etc.
Graphene and Me: My Brush with the Wonder Material
Graphene, a two-dimensional honeycomb lattice of carbon atoms, has made waves in science and technology circles. Last week, I gave a brief overview of the history of the stuff and why it’s special. This week, I’d like to continue the story by talking about applications. Unfortunately for us—and fortunately for society as a whole—graphene has spawned so many new technologies that it’s impossible for me to discuss them all. So instead, I thought I’d talk a single application that has personal value to me. As an undergraduate student, I spent two years in a laser lab studying graphene’s applications
optics / Physics / Quantum Mechanics / etc.
Mode-Locked Lasers: The Beating Pulse of Metrology
Your hand opens and closes, opens and closes. If it were always a fist or always stretched open, you would be paralysed. Your deepest presence is in every small contracting and expanding, the two as beautifully balanced and coordinated as birds’ wings. ~Rumi Although we don’t usually notice them, ultrafast pulsed lasers are all around us. They are keep time in the atomic clocks on GPS satellites. Metrologists and chemists use them to measure the properties of atoms and molecules. Astronomers use them to measure the color of light from distant stars. Particle physicists use them in supercollidors. Materials