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

Condensed Matter / optics / Physics / etc.

Graphene: The Story of the Wonder Material

I call our world Flatland, not because we call it so, but to make its nature clearer to you, my happy readers, who are privileged to live in Space. ~A. Square In the past few years, you’ve probably heard something about graphene—whether as a replacement for silicon, as the next generation of organic solar cell, as the material in fast-charging batteries, or as one of the strongest materials ever discovered. There’s been so much hype that people have begun calling the flood of research and investment the graphene gold rush. In this post, I’ll give you a brief primer

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

optics / Physics / Quantum Mechanics / etc.

Scattering Part Two: A Quantum of Scattering

We come spinning out of nothing, scattering stars like dust! ~Jalāl ad-Dīn Muhammad Rūmī Last week, I explained Rayleigh and Raman scattering from a classical point of view. In the process, I explained why the sky is blue and introduced Raman spectroscopy, a powerful tool for studying the structure of molecules. This week, I fill in the gaps and explain scattering from a quantum-mechanical point of view. Before we can talk about scattering, though, we need to review some important ideas from quantum mechanics: energy levels and the Heisenberg uncertainty principle. Energy Levels The story of energy levels starts

optics / Physics / Quantum Mechanics / etc.

Why The Sky is Blue: Lord Rayleigh, Sir Raman, and Scattering

The Sky is the Daily Bread of the Eyes ~Ralph Waldo Emerson   At some point in his or her life, almost every child on Earth asks, “Why is the sky blue?” The question is so prevalent that, to me, it has come to represent the wonder that the world holds for a a child. Adults don’t ask such questions… at least, not unless they’re scientists. Part 1: John Tyndall In 1859, physicist John Tyndall thought he’d found the answer to the sky’s color. His studies of infrared radiation required him to use containers of completely pure air. He

optics / Physics / Quantum Mechanics / etc.

How Things Work: Lasers

You know, I have one simple request. And that is to have sharks with frikkin laser beams attached to their heads! ~Dr. Evil Always look on the bright side …unless you’re holding a laser pointing device. ~Unknown The laser is, without a doubt, one of the most ubiquitous, archetypal technologies of modern times. And it is one of the most direct applications of quantum mechanics.  But how do lasers work? It All Starts In The Atom The story starts deep within the atom. I’ve previously discuss the fact that particles are waves and that this forces electrons to have