Opto-Electronics for Communications: Spectrum Analysis

Opto-Electronics for communications Spectrum AnalysisThis examine studies the wavelengths of the an nonates in the spectrum of a fall down point of reference. I will measure the angle at which colour splits. I will carry out(p) this test with third divergent smartnessen man-make lakeswest well-to-do-emitting diodeLaser crystal rectifier dispirit outgrowth SpectrumThe electromagnetic spectrum describes apiece the wavelengths. It sites from the smallest waves possible, radio waves to the hugest waves, Gamma radiation. All antithetic size waveforms have different functions.EnergyFrequencyWavelengthRadiation typeTypical use lowLowestLongestRadio wavesTelevision signalsMicrowavesCooking, mobile phonesInfr a rose-cheeked optic fibre communication panoptic smartnessSeeing in palpable detect forged bank notesX-raysMedical watchs of bones luxuriouslyestHighestShortestGamma radiation sidesplitting potbellycer cellsThe only Electromagnetic waves we coffin nail depend ar gon Visible Light Waves. We see manifest washy waves as colours of the rainbow. from each one different colour has its own wavelength different to the early(a)s. The longest wavelength is Red, with the shortest wavelength being Violet. The cabal of all the miniature wave colours makes discolour elation.DiffractionWe can see each colour of the Visible unhorse spectrum by shining a tweed kindling through a prism. By diffraction, the whitenness ethereal-hearted splits apart into different colours of viewable light. Water vapour can carry out the same effect of diffraction, and the outcome is a rainbow.GratingsA diffraction grating is a slide with a number of parallel slits gaunt on it. The slits are genuinely small, usually 600 per 1mm. When a beam of light is directed at the grating, light will diffract of it and the light is dot in certain directions only. This is coarsely apply to separate colours of the resultant light because the diffracted light has differen t angles according toAll equipment utilise for this experiment was taken from the PASCO Educational Spectrophotometer Accessory Kit merry-go-round Motion sensorAperture BracketLight character referencePASCO data eruditeness softwareHigh Sensitivity Light SensorEquipment frame-upSet up the Spectrophotometer b orderinging to your chosen light obtain as shown in Figure 2. clothe the light character reference with Collimating Slits so it transmits a thin 0.5 to 1.0 cm beam. A hood should be apply ein truthwhere the light base to take up any distortion in the experiment results.Align the light source. call on on the light source and align the light beam by adjusting the Collimating Slits, Collimating Lens and Focusing Lens so a clear image of the central ray appear on the light sensor. refer the Light Sensor and Rotary Motion Sensor to channels A and B of the PASCO computer interface.Software frame-upOpen the PASCO data eruditeness software. link Digital channels 1 and 2 to the Rotary Motion Sensor. Connect Analog Channel A to the Light Sensor.Set up parameters for the Rotary Motion Sensor. A sample rate of 20 Hz with a high resolution of 1440 Divisions per Rotation.Use the PASCO softwares calculator function to calculate the positive Angular slip based on the Angular Position metre made by the Rotary Motion Sensor. The measured Angular Position should be divided by 2.Data Recording SetupIn the PASCO data acquisition software, select the graph mode.Select the upended axis as Light Intensity, and Horizontal axis as effective Angular Position.Turn off the lights in the laboratory to ensure the results are as accurate as possible and no endorseground light interferes.On the top of the light sensor select the appropriate raise setting. Different light sources will require different settings.Select capture Recording DataTurn the light sensor slowly in one complete circle. This will scan through the first order spectrum lines and data will be record ed in the PASCO data acquisition software.Select Stop Recording DataData Analysis SetupThe size of the wavelength can be calculated by analysing the results of the experiments and using the gratings equation. By using a visible light spectrum, we can determine what colour the light is from the size of the calculated waveform. WavelengthMeasure the two gushs, R1and R2Use the visible light wavelength spectrum below to find out what the wavelegth iswest Light SourceDating back to the 1800s, west light sources are the oldest and most tested light source invented. They first became commercialised by Thomas Edison at the end of the century, leading on to the first light fittings, named after(prenominal) Edison himself. The Edison get along or ES.A Tungsten filament is the key element to a Tungsten light source. Light is emitted from the filament when it is heated. The filament is heated by passing circulating(prenominal) through it. This is possible because of the high amount of curr ent passing through such a small conductor. Inert gasoline such as Argon usually surrounds the conductor to ensure that it does not ignite. 95% of the dynamism from a Tungsten light source is penni slight in the form of heat. Only 5% of the energy is actually used in the form of visible light. This makes it a very inefficient light source.Being a blackbody radiator, a Tungsten light source has a continuous spectrum of light. It generates a high amount of red light compared to natural day light, which gives it the yellowed tint. Beyond the visible light spectrum a Tungsten light source even emits infrared wavelengths. This is a decompose of energy as it cannot be seen by the human eye.On the side by side(p) page are the results from the PASCO data acquisition software whilst carrying out the experiment procedure using a Tungsten light source. The light sensor was set to have a take a shit setting of 100 because of the large spectrum that the wavelength pass throughs. apex of t he suns way to peak wavelengthInfrared WaveformTrough to gutter ultraviolet WaveformMy experiment results show that the Tungsten light source is emitting wavelengths in the range of 317.88 to 895.14nm. The Tungsten light source is a warm white light as well as Infrared and Ultraviolet light. take Light SourceA conduct or Light Emitting Diode is a semiconductor that gives out light when current is passed through it. It is a very much more efficient method of emitting light compared to more stuffy light sources such as Incandescent lights or Fluorescent lights because little heat is generated, resulting in less heat loss.As well as being more energy efficient compared to Incandescent light sources, lead light sources have a much longer operational time. At the end of an Incandescent lights life the filament will burn out, resulting in the bulb not emitting light. A light-emitting diode light source after 50,000 hours of use will start to become dimmer and emit less light. The re sult of this is a light source that lasts a lot longer.The first commercial lead light sources developed were by Hewlett Packard in 1968 to commute indicator lamps. At this time, only leads emitting red light were available. Only afterwards on in 1994 were directs that emitted olive-drab light first demonstrated by Isamu Akasaki and Hiroshi Amano, who went on to be awarded the 2014 Nobel Prize in physics for their discovery. With the invention of blue coloured LEDs, the invention of white LEDs became apparent. The white LED is a compounding of LEDs that emit red, green and blue light. This then led to the LED light source revolution we currently live within.The working principle merchantman a LED is what is called a P-N Junction. A P-N junction will permute electric current into visible light. This is often called electroluminescence.ColourWavelength (nm)Typical secular UsedInfrared 760Gallium arsenideRed610 to 760Aluminium gallium arsenide orange590 to 610Gallium arsenide phosphideYellow570 to 590Gallium arsenide phosphideGreen500 to 570Gallium phosphide savoury450 to 500Zinc selenideViolet400 to 450Indium gallium nitrideUltravioletIndium gallium nitrideWhiteBroad SpectrumCool white is a blue LED combined with a yellow phosphor.Warm white is a blue LED combined with a orange phosphor. tabular array 1 Wavelengths of each colour LEDAbove is a dishearten outlining the individual wavelengths for each colour that is produced by Light Emitting Diodes.The most common type of LED light source shines line in a single direction. The result of this is a light bulb that only lights up a small empyrean. To correct this problem for use as light sources to light up areas and not as indication lights, most LED light sources are coupled with reflective plates that distribute the light equally around the room.On the next page are the results from the PASCO data acquisition software whilst carrying out the experiment procedure using a LED light source. The light se nsor was set to have a gain setting of 100 because of the large spectrum that the wavelength covers.Peak 1Peak to peak wavelengthYellow WaveformTrough to stadiumGreen WaveformPeak 2Peak to peak wavelengthBlue WaveformTrough to troughBlue WaveformMy experiment results show that the LED light source is emitting visible light in the ranges of 388 to 473nm and 514 to 583nm. The LED is emitting a combination of yellow and blue to pass water a cool white colour.White LEDBy combining yellow and blue waveforms, a cool white colour is formed. This is carried out by lining a blue LED with yellow phosphor. Both yellow and blue photons are emitted. This method of creating white light is much more effective than the more conventional LED RGB method of combining red, green and blue waveforms. This effect was discovered by Sir Isaac Newton in the early 1700s when he was performing colour co-ordinated experiments.The colour temperature of the white LED light source is controlled by the weightine ss of the yellow phosphor that is coated onto the blue LED. Over time, the yellow phosphor will take down and so the colour characteristics of the LED light source will change. operating(a) at high temperatures can accelerate this.Laser Light SourceLaser is an acronym of Light amplification by simulated emission of radiation. A laser light source emits light when electrons in the atoms of gases become kindle by absorbing energy from electrical current. Electrons blend in from the lower energy point to the higher energy point around the atoms nucleus. When they travel back from the higher point to their resting state the electrons emit visible light.The wavelength of the photons emitted are ageless and coherent, unlike ordinary visible light from other light sources. This office that only one wavelength of light is emitted from a laser light source, resulting in only one specific colour. Also because of this, the light is not diffuse like a conventional light source. The light e mitted is a very tight beam. The result of this is a beam of light that can travel much further than other light sources.By harvesting the differentiate powerful light, laser light sources have various applications such asEntertainment Laser light shows are created by bouncing different lasers into each other to create special effectsComputing Lasers can be used as a form of communication due(p) to the high speed of light. The most common application is fibre optics. toil Due to the high amount of energy concentrated in a laser light source, they can be used in yield to cut a range of materials.Optical Fibre Communications data in the form of coded light of infrared signals are carry across Optical Fibres. The information carried across Optical Fibres can be much more than an ordinary copper data cable of the same diameter. An ocular fibre is a very thin shard of glass. Next to no light is absorbed by the glass. Light is carried from one end to the other by total internal ref lection (TIR), even when the fibre is bent. The signals in visual fibres do not weaken as much over long distances as the signals in ordinary cables.The laser diode that is used for optical fibre communications is typically either 850nm, 1300nm or 1550nm. This bureau that the waveform used is in the infrared field of the electromagnetic spectrum. We use infrared because the attenuation if the fibre is less at infrared wavelengths.On the next page are the results from the PASCO data acquisition software whilst carrying out the experiment procedure using a LED light source. The light sensor was set to have a gain setting of 10 because of the small spectrum that the wavelength covers.Peak to peak wavelengthRed WaveformTrough to troughRed WaveformMy experiment results show that the laser light source is emitting visible light in the range of 624 to 690nm. The laser is emitting a red light.The overall results of the spectrum experiment look unique to each other. All three light sources have different spectra to each other. The Tungsten light source has a wide range across the spectrum covering all the visible colours, as well as ultraviolet light to infrared. The LED light source has a much smaller range across the spectrum compared to the Tungsten light source by only emitting waveforms that combine colours to create a cool white effect. The Laser light source had the smallest range on the visible light spectrum, only covering the colour red. This light source is much more concentrated on one area of the spectrum compared to the other light sources.From the results, I can see why each type of light source is used for its applications. Tungsten light sources cover all colours within the visible light spectrum, and so they are good for illuminating objects, in the form of a light bulb. LED light sources only cover specific colours within the visible light spectrum, and so they are good for indication lamps and signals. Laser light sources only cover one area of th e light spectrum and therefor used for communications.Laser diode light sources are the key piece of equipment for optical communications because of the small wavelength that they emit. This small wavelength can be interpreted as data signals and used as optical communications.The overall results of this experiment where great. The result were exactly how I predicted them to be. If I could change anything about the experiment, it would be the Tungsten light source. I would use a larger light source as the Tungsten light source used was not very effective during the experiment.Dr Yongkang GongUniversity of South Wales LecturerFor teaching me about light wavesChristopher EdwardsAlex HoustonDaniel PriceUniversity of South Wales StudentsFor taking part in this series of experiments.BBC. (n.d.). insane asylum to light waves. Retrieved from BBC Bite Size.Lighting Research Centre. (n.d.). How is white light made with LEDs? Retrieved from http//www.lrc.rpi.edu/programs/nlpip/lightingAnswer s/led/whiteLight.aspNASA. (n.d.). What Wavelength Goes With a Color? Retrieved from https//science-edu.larc.nasa.gov/EDDOCS/Wavelengths_for_Colors.htmlPASCO. (n.d.). Educational Spectrophotometer Accessory Kit and System.Photon Start. (n.d.). How LEDs induce White Light. Retrieved from http//www.photonstartechnology.com/learn/how_leds_produce_white_lightPhysics Education. (n.d.). What is electromagnetic radiation? Retrieved from http//cmb.physics.wisc.edu/pub/tutorial/spectrum.htmlPhysics Forums. (n.d.). LED light diffraction . Retrieved from https//www.physicsforums.com/threads/led-light-diffraction-scattering.211563/Science World. (n.d.). Retrieved from Wolfram http//scienceworld.wolfram.com/physics/SnellsLaw.htmlSnells Law Explained. (n.d.). Retrieved from Hyper Physics http//hyperphysics.phy-astr.gsu.edu/hbase/geoopt/refr.htmlThe Law of Refraction. (n.d.). Retrieved from Math Fundimentals https//www.math.ubc.ca/cass/courses/m309-01a/chu/Fundamentals/snell.htmTIR. (n.d.). Retrie ved from Physics descriptor Room http//www.physicsclassroom.com/class/refrn/Lesson-3/Total-Internal-ReflectionX-Rite. (n.d.). What is a spectrophotometer? Retrieved from http//www.xrite.com/learning/other-resources/what-is-a-spectrophotometer