Simple Arduino Quantum Dynamics Laser Project

Simple guide to using an Arduino with a Laser to test Quantum Dynamics of Light for yourself.

Guide

Simple Arduino Quantum Dynamics Project

Introduction

This tutorial will introduce you to the world of Arduino by setting up an environment to see the cool effects of quantum dynamics of light for yourself!

Components

All the components needed for this project is available on our Leobot Electronics store. 

1) Arduino Uno available here.

2) KY-008 Red Laser Module available here.

3) Male-to-Female jumper cables available here.

4) Prism available here

The Arduino will be used to control the KY-008 Laser Module and, the jumper cables will simply be used to connect everything together.

Key Component Information

Since the main module that we want to control via the Arduino is the KY-008 Red Laser. Therefore, some explanation is provided about how to operate this module before we delve into the code needed to operate it.

KY-008 Red Laser Module

The module has three pins:
Pin 1: Vdc
Pin 2: Reference (Ref) (Not Needed)
Pin 3: Ground (GND)

Vdc is the voltage supplied to power the laser; Ref provides a backward reference voltage that we will not be using or needing; GND is simply the ground area of the circuit.

The KY-008 Laser Module has operates in the range below 5V power supply and a max of 35mA current usage therefore is well suited for Arduino. Lower voltages can also be used but the brightness of the laser will be more dim.  

Arduino Connections

1) Connect Vdc of the Laser module to Pin 2 of the Arduino.

2) Connect GND of the Laser module to any GND on pin on the Arduino.

That is it for circuitry!

Arduino Code

Here we will simply provide the code to turn the Laser on and off at specific delayed time intervals:

// KY-008 Laser Transmitter Demo

int Laser = 2; // creating a variable named Laser and assigning it to digital pin 2

void setup() {

pinMode (Laser,OUTPUT); // designating pin 2 as output (we can use "Laser" instead of the pin # because we assigned "Laser" to pin 2 above)

digitalWrite(Laser,LOW); // making sure the laser is off at startup or reset

}

void loop() {

digitalWrite(Laser,HIGH); // turning the laser on

delay(250); // waiting for 1/4 of a second

digitalWrite(Laser,LOW); // turning the laser off

delay(250); // waiting for 1/4 of a second

/* That's it, the code will repeat itself (from "void loop" down) over and over until you pull the plug. You can go ahead and play with the "delay" times for faster or slower on/off speeds */

}

Now we have the Laser up and running we can do some really cool experiments already but we want add a Prism to our experiment to pierce at the core of how light acts.

The Prism itself will act as a beam splitter and can be controlled by the angle at which the laser hits the Prism. 

By using smoke, we can visibly see the lines emitted by the laser if we are unsure of how exactly our beam is being split. If we add another Prism to the system then we can have a beam-splitter that will split the light into an exactly perpendicular direction to each other.

To keep things simple, we will use only one Prism and do an experiment that I myself never cease to be amazed at and simply call 'Fluid Motion Magnification' for a lack of better wording.

Fluid Motion Magnification

This experiment can be seen in a multitude of ways but I wish to show to setup what we have so far to "magnify" water to such an extent that we can see the minutest action in great detail. 

The steps needed require specific accuracy but is very easy for get right if you consider that you can at any time see your laser lines by using a bit of smoke to help if needed.

1) First, we want the laser to point at a flat surface, such as a table, at a 45-degree angle. If is not exactly 45 degrees then that is fine too since can easily adjust the Prism to get an effective 45-degree angle.

2) Next, we need to place the prism, flat on the surface but at a distance that the center point of the laser hits the prism exactly at the point where it touches the surface. It is easy to observe if done correctly: there will be a straight light emitted on the surface behind the prism. By moving the prism back and forward the optimal point can be found where the lines on the flat surface is at a maximum. Accuracy is not crucial but beneficial. 

3) Get a glass of cold water then place it at a distance so that that top laser from the split laser-beam hits the glass at the point where the fluid meets the glass. If you have a cold fluid that condensates on the outside, you will immediately start observing effects on the wall behind the glass. As the condensate water gets heavy enough to fall down then you will observe this in great detail by watching the laser light on the wall. If you used a fuzzy drink such as cola, then you will observer all sorts of amazing interactions as bubbles form, buoyancy forces the bubbles to the top and there the bubble may stay intact if it has enough surface tension or may explode if the surface tension force is overcome. 

4) If the glass of water or fluid has reached a state of equilibrium then still watch the fluid in motion by moving fluids around on the outside of the glass. Every particle of water moving past the beams will effectively create a small prism that can be observed by watching the motion of the light on the wall itself instead of the glass where to the naked eye there may be very little motion or even none at all.

Beam Splitting Water Glass

If you do not have a Prism then there is another easy way to hack together a beam-splitter by using water and a glass. It will effectively split your beam into 2 beams that are exactly opposite in direction to each other, and at a height difference that is the height of the water level in the glass. 

1) Get a raised flat surface (such as a book) for the laser to shine on at an angle of 45 degrees.

2) At the edge of the flat surface, place the glass of water, itself on a flat surface (such as a table).

3) If the glass is at the right distance, a beam will be clearly visible on the table (as though there was a Prism), the other beam will be directly in the opposite direction at the top of the glass at the same height as the laser itself.

You will effectively have 6 beams exiting the glass at the top and 1 beam exiting the glass on the surface itself too, directly ahead of the emitter but way below on a parallel surface!

Laser-lit Water Light

To change laser light from a directional motion to a radial motion, we simple need a circular container of liquid such as water.