Degree Project in Engineering Physics, First Level SA114X

Optimization and Demonstration ofa Fiber-Optic GyroscopeBachelor Thesis in Applied Physics, KTH

Authors:

Frans ForsbergOla Sjölander

fransf@kth.seolasjol@kth.se

Supervisors:

Marcin SwilloGunnar Björk

marcin@kth.segbjork@kth.se

May 16, 2016

Abstract

Fiber-optic gyroscopes play an important part in modern engineering.They are frequently used in transport systems, land surveying and in awide variety of military applications to measure angular velocity. Conse-quently, it is of importance to be able to demonstrate the effects of sucha component in a simple fashion for educational purposes.

The goal of this bachelor thesis is to create an easy way to show theproperties of a fiber-optic gyroscope. This will be done by creating a user-friendly visual display and an in-depth guide on how to operate and makecalibrations for an existing gyroscope. It is important to note that thecalibrations and optimizations are made for this particular apparatus andthus will not necessarily be applicable to similar constructions. The gyro-scope itself uses a 1550 nm infrared laser beam that is split and coupledinto opposite directions of a 14 km long coil of optical fiber. The beamsare subsequently made to interfere and then measured. The measurementconsists of a voltage signal that corresponds to the phase shift between thetwo beams. Thus rotating the gyroscope will change the voltage outputwhich may then be translated to angular velocity.

The tasks involved in this project will begin with finding the optimalsignal. This is done by aligning the optical components using a visibleHeNe laser with 632.8 nm wavelength. Then changing to the infrared laserand making careful adjustments to find the appropriate voltage output.Furthermore, the signal has to be transferred to a computer, which is donethrough an analog-to-digital converter. Once the signal can be detected,a visual interface can be created to show and use the voltage on thecomputer. The end result is a fiber-optic gyroscope with a useful displayfor demonstrations.

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Contents1 Introduction 3

2 Prerequisites 42.1 Optical setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42.2 The Sagnac interferometer . . . . . . . . . . . . . . . . . . . . . . 62.3 Phase shift and output voltage . . . . . . . . . . . . . . . . . . . 8

2.3.1 Angular velocities . . . . . . . . . . . . . . . . . . . . . . 10

3 Procedure 103.1 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3.1.1 Visible light . . . . . . . . . . . . . . . . . . . . . . . . . . 113.1.2 Infrared light . . . . . . . . . . . . . . . . . . . . . . . . . 12

3.2 Electrical setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133.3 The phase quadrature point . . . . . . . . . . . . . . . . . . . . . 153.4 User interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.4.1 Experimental evaluation . . . . . . . . . . . . . . . . . . . 163.5 Reduction of noise . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4 Results 17

5 Analysis 185.1 Angular drift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185.2 Further additions . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

6 References 19

7 Appendix 197.1 Responsibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197.2 LabVIEW version and license . . . . . . . . . . . . . . . . . . . . 197.3 National Instruments drivers . . . . . . . . . . . . . . . . . . . . 19

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1 IntroductionGyroscopes have been utilized for navigation and localization purposes for about200 years, for most of this time there have only been mechanical gyroscopes.Military interest in this instrument around the time of World War II acted asa catalyst for innovations within this area, as it did for many other technolog-ical advancements. As areas of application became more exotic and demandedhigher precision and more versatility, the mechanical gyroscope simply couldnot keep up.

Today, fiber-optic gyroscopes are widely used in many navigation systems,such as those in satellites and airplanes. This makes the fiber-optic gyroscope avery impactful and important instrument in modern technology, and thereforeit is beneficial to have a basic understanding of how it works. The primarygoal is derived from this reasoning, namely to educate others using a simpledemonstration with a user interface that is easy to understand and operate.

A fiber-optic gyroscope has already been created for educational purposes,but it was lacking the optimization and visual display required to make a usefuldemonstration. Using this prototype gyroscope as a basis for the project, therequirements to achieve the goal become clear. Firstly, the optical setup of thegyroscope has to be calibrated and optimized such that a good voltage outputis obtained. Secondly, converting this output into a signal that can be read bya computer. Lastly, creating a user-friendly interface that uses the signal tocalculate the angular velocity and to display the rotation of the gyroscope. Thefinal product should be a demonstration tool useful in lecture environments.

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Figure 1: The internal optical setup of the gyroscope.

2 PrerequisitesBefore the calibration can be done, it is required to know how the gyroscopeworks. This includes all the optical equipment as well as the theory behind it.In this part, all of the prerequisites will be covered.

2.1 Optical setupThe setup and all the components are shown in figure (1). The key to makinga fiber-optic gyroscope is to measure a phase shift between two beams of light.A phase shift is the difference in angle between two sinusoidal waves. Such ameasurement can be achieved by allowing light to travel in opposite directionsof a long coil. When the coil is rotated, light travelling in one direction will havea slightly longer optical path than the light travelling in the opposite direction.Then, if the beams are joined, a phase shift is obtained and may be measuredusing a detector, converting the shift into a voltage output. This gives theability to relate mechanical rotation speed to an electrical signal which is themain purpose of a modern gyroscope.

Within the gyroscope a 1550 nm laser is incorporated, which generates thedefault beam for this apparatus. Visible light may also be used if rough align-ments are to be made. However, it is worth noting that the visible light will notbe able to pass through the coil. This is due to the wavelength being too short,

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causing too large of an attenuation to be detected at the other end.The components shown as green or blue curves in figure (1) are the SMF-

28™optical fibers. This is a singe-mode fiber, meaning that it only allows onemode of light to propagate. This is important as different modes of light trav-elling through a fiber can behave differently, resulting in many different phaseshifts that cannot be distinguished by the detector. A single-mode fiber ensuresthat only one phase shift is present and that this is the one that is detected.

The effective group refractive index n28 = 1.4682 [1] is used for the fiber.This is the index for a photon wave package travelling along the fiber. Onemay note that the index is slightly different in this case because a continuouslaser is used and not photon wave packages. However, this small distinction isirrelevant for this project. The index and other important parameters for thegyroscope are assembled in table (1).

Symbol Description Value Unitn28 The SMF-28™effective group index of refraction. 1.4682v28 = c/n28. Speed of light inside the fiber. 2.044 · 108 m/sRc Radius of coil. 0.08 mLc Length of coil. 14 474 m

Table 1: Necessary parameter values of the components.

When the light from the generator leaves the first fiber, it is collimated bya lens to create a beam outside of the fiber. Subsequently, it passes through a50/50 optical beam splitter mainly used to allow the light to pass into the detec-tor later on. This is the first stage of the optical setup and includes componentslabelled 2, 3, 4 and 10 in figure (1).

The second stage of the optical setup is more complex. As previously ex-plained, the light has to be divided into two beams and forced into the oppositedirections of the coil. To be able to do this properly, a 45o polarizer is used toonly allow light with 45o polarization to pass through. Now, the beams can besplit using a V/H beam splitter, allowing horizontally polarized beams to passthrough and vertically polarized beams to be reflected perpendicularly to theincoming beam. The beams may then move through the coil to the oppositeends. However, if one observes the light coming in and out of the lens labelled7, horizontally polarized light should be going in and vertically polarized lightshould be coming out. Looking at the setup in figure (1), one may see thatlight coming out of this particular lens has to pass through the V/H beam split-ter to reach the 50/50 optical beam splitter. However, since the light comingout is vertically polarized, be reflected by the V/H beam splitter. Thereforethis light has to be horizontally polarized, meaning that it has to be changedwhile travelling to and from the coil. To solve this, quarter wave plates areused to introduce an additional phase shift of π/2 between the basis vectorsof the passing light. Consequently, the vertically polarized beam will obtain acircular polarization before going into the fiber at 11, ultimately resulting in ahorizontally polarized beam when it passes through the quarter wave plate after

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Figure 2: A photograph of the optical setup.

exiting 7. The same applies for the horizontally polarized beam, which becomesa vertically polarized beam. With these components in place, the beams can bereflected or pass through the V/H beam splitter appropriately.

When the beams are joined and travelling backwards in the setup, they arereflected by the 50/50 beam splitter towards the detector. The setup concludeswith the detector seen in figure (7) where the phase shift is translated to volt-age output. The only component not directly related to the beam path is thepolarization controller labelled 8 in figure (1). This apparatus is mainly used tocounteract twists and bends in the optical fiber that may occur when the fiberis looped around the coil.

2.2 The Sagnac interferometerThis method of introducing a phase shift is characteristic for the Sagnac inter-ferometer. This phase shift is created when the coil rotates, causing photonstravelling in opposite directions of the fiber to remain inside the coil for differ-ent amounts of time. Defining the rotary axis as the normal vector pointingout of the Earth’s surface one gets positive angular velocities ω in the counterclockwise direction in the coil. The time one beam spends in the coil when thegyroscope rotates can then be calculated as

t1 =Lc

v28 −Rcωin the counter clockwise direction. Similarly, in the clockwise direction:

t2 =Lc

v28 +Rcω.

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However, one also has to take relativity into account. With Lorentz transfor-mation, the speed of light propagating through the fiber becomes

v28 −Rcω ⇒ v28 −Rcω +Rcω(1− 1

n228) = v28 −

Rcω

n228

in the clockwise direction. Likewise, in the clockwise direction, one gets

v28 +Rcω ⇒ v28 +Rcω −Rcω(1− 1

n228) = v28 +

Rcω

n228.

Hence, the Lorentz transformed times are

t1 =Lc

v28 −Rcω/n228

t2 =Lc

v28 +Rcω/n228.

With this, the time difference between the two beams is

∆t = t1 − t2 = Lcv28 +Rcω/n

228 − v28 +Rcω/n

228

v228 −R2cω

2/n428=

2LcRcω/n228

v228 −R2cω

2/n428

With c = n28v28, one finally arrives at the expression

∆t =2LcRcω

c2 −R2cω

2/n228. (1)

Furthermore, the phase shift is calculated as

∆φ =2πn28λ

v28∆t. (2)

Now, using (1) in (2) the following equation is obtained:

∆φ =2πc

λ

2LcRcω

c2 −R2cω

2/n228(3)

This equation will be useful later on when translating voltage to angular velocitysince the change in voltage output only depends on the phase shift.

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2.3 Phase shift and output voltage

Figure 3: Output voltage as a function of the phase shift. This is the voltage measured with φ0 = 0.

The voltage signal may be obtained by connecting the electrical output of thegyroscope to an oscilloscope. If the optical setup has been calibrated, a signalshould be seen as a straight line with some minor fluctuations. The strengthof the signal is dependent on the phase shift and how the joined beams hit thedetector. The voltage signal detected is determined by

V = V0

(cos(φ0 + ∆φ) + 1

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), (4)

for the horizontal axis of the detector lens, shown in figure (4), where φ0 isthe position of the detector, ∆φ is the phase shift and V0 is the peak voltage.By tilting the detector lens, the value of φ0 may be changed, providing theability to choose the point of detection relative to the interference pattern. Thegraph shown in figure (3) relates to the intensity peaks of interference patternmeasured at the horizontal axis. If a phase shift is introduced, the peaks moverelative to the point of detection, resulting in a voltage change.

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Figure 4: Light hitting the detector lens. The red ellipses are the interference pattern created bythe joined beams. The black square is the point of detection φ0. The blue peaks are the voltagepeaks shown in figure (3).

If the joined beams are perfectly aligned to the center of the detector, thenφ0 = 0 and the oscilloscope will show the peak voltage if no phase shift ispresent. Once an angular velocity is introduced, the voltage changes accordingto the phase shift. However, looking at figure (3), one may note that if theoptical equipment is perfectly aligned, then phase shift in either direction willresult in a decrease in voltage. Thus it is impossible to distinguish the directionof rotation. Since it is important for demonstrational purposes to be able tomake this distinction, a small recalibration is required. The recalibration isperformed by moving the detector to the phase quadrature point, the pointwhere φ0 = ±π/2. Here, the voltage will either increase or decrease dependingon the direction of phase change. Consequently, it is possible to distinguish thedirection of rotation.

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Figure 5: Voltage versus angular velocity ω. One may notice that the closest maximum lies atω = −2.88 and the closest minimum at ω = 2.88. This is the voltage measured with the detectorat φ0 = π/2, the phase quadrature point.

2.3.1 Angular velocities

According to equation (4) and figure (3) the voltage appear periodic as phaseshift increases. Now, using equation (3) one may arrive at the result shown infigure (5). Here, the relation between voltage and angular velocity is presented.

By measuring at the phase quadrature point the allowed values for the an-gular velocity will be between the closest maximum and minimum of the graph.If the angular velocity corresponds to the maximum or minimum voltage, it isimpossible to distinguish between increasing or decreasing the angular velocity.If the output voltage is used to measure the angular velocity, which it is in thiscase, this has to be taken into account. The best way to prevent this is simplyto prohibit high rotational velocities. Thus, once again looking at figure (5),one may see that the allowed values of angular velocities lie within the range of-2.88 and 2.88 degrees per second.

3 ProcedureIn this section the most important aspects of this project will be described. Thisincludes firstly how the calibration was made and how to get a good signal towork with. Secondly the output voltage has to be translated into a signal thatis compatible with a computer with the appropriate software. For this projectthe program LabVIEW was used in order to easily detect and use the obtainedsignal. How to download LabVIEW and the adequate drivers will be explainedin the appendix. Lastly the adjustments made for educational purposes will be

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explained along with how the user interface is built and how the backgroundnoise was dealt with.

The procedure is written not only as a report but also as a comprehensiveguide for future students or teachers. This is due to the nature of the project,that it is mainly made for others to use. The equipment is sensitive and therisk of the gyroscope becoming misaligned is quite large. Thus it is importantfor users to be able to realign and recalibrate the gyroscope.

3.1 CalibrationThe calibration is divided into two parts. The first part is a coarse alignmentusing visible light so that it is easily seen if the components are roughly aligned.Subsequently, the default infrared light will be used to make finer adjustments,this is the second part of the calibration. Since the infrared light is invisible tothe naked eye, some other method of detection needs to be used. One can usea detector connected to an oscilloscope in order to achieve this. There is onesuch detector included in the gyroscope, a detailed description of how to setthis up can be seen in the Electrical Setup section. The only difference is thatthe electrical output of this detector should be connected to an oscilloscope.Moreover, calibration is only necessary if no signal is achieved, or if the voltageoutput is lower than 10 V when using the included detector.

If the signal exists but is lower than 10 V, only small adjustments may beneeded without changing the alignment. Adjusting the rotatable parts of thepolarization controller shown in figure (6) may increase the signal strength. Ifthat is the case, then the output has been reduced due to twists in the fibers.Now, if the signal still is too low, increase the output of the infrared laser. Donot let the signal move above 10 V as it will saturate the detector. This will haveto be done each time the gyroscope is to be used as it is the most likely cause ofreduced output signal. If this does not help, or the signal is non existent, thenalignments of the optical components will have to be made.

3.1.1 Visible light

The first part of the calibration involves using a visible light source connectedto different parts of the optical setup. This is, as explained, a very roughcalibration only to be used if no signal is present when using the infrared light.To make a good alignment all parts of the optical setup needs to be checked. Asan example, looking at figure (1), if the visible light is connected to component3, one should check the lenses 7 and 11 to see if there is any light. The knobs on3 may then be rotated to move the beam. It is helpful to use a piece of paperto see if the laser hits the center of each lens. If it does, continue to rotate theknobs slightly while looking into their respective connected fibers to see whenmaximum intensity is achieved. The goal is to have the light going to 7 and11 to have equal intensity. If this is difficult to achieve, try rotating the 45opolarizer to allow more vertical or horizontal light as needed.

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Figure 6: A photograph of the polarization controller.

One may apply the aforementioned strategy to all combinations of compo-nents. This includes connecting the light to 7 or 11 and checking lenses 3 and 10while rotating the knobs on 7 or 11, as well as connecting to 10 while checking 7and 11. As mentioned before, note that the visible light cannot travel throughthe coil because the attenuation is too high for this wavelength. This meansthat one cannot use the green fiber to test the alignment. Hence, to check thewhole setup, 7 needs to be connected to 11 directly. Pay attention to twistsor sharp curves in the fibers as they may remove a large portion of the light’sintensity.

3.1.2 Infrared light

Once the rough calibration has been made, the same approach may be used forthe infrared light. However, now the fibers leaving the lenses will have to beconnected to the detector which in turn needs to be connected to an oscilloscopeas explained before. At this point, a signal should be seen between all of thecomponents. Thus one can easily make fine adjustments to the rotational knobsin order to increase the output signal. Connecting the detector also means thatdifferent output lenses cannot be checked simultaneously. Hence it is importantnot to change the alignment of 3 or 10 too much while checking 7 or 11, as bothare affected by such adjustments.

Ultimately, the whole setup should be tested by reconnecting the light sourceto 3 and the detector to 10. Continue to do fine adjustments to all the compo-nents until a maximum signal of at least 10 V is reached when the laser is atmaximum power. If a larger signal is had, adjust the power of the laser suchthat the maximum signal is 10 V. Once it is done and the gyroscope reactsnicely to rotation, the signal can be used for measurements.

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3.2 Electrical setup

Figure 7: The electrical connections between the power supply and detector.

In order to gain useful information from the gyroscope it is necessary to createa good electrical setup for the detector. A power supply is used for the detectorproviding a voltage range of ±15 V, the power of the laser is adjusted such thatthe maximum measured output signal is 10 V as to not saturate the detector.Besides receiving the voltage input from the power supply, the detector is alsogrounded. The output signal from the detector is then led to the analog-digitalconverter via the setup shown in figure (8). The converter’s ports are pairedtogether to allow measurement based on a reference signal. Paired ports arespaced four apart, so the setup that is used involves the ports Analog Input 0(ai0) and Analog Input 4 (ai4).

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Figure 8: The connection setup to the analog-digital converter.

The converted digital output signal is then readable and processable bythe user interface. This setup creates a strong enough output signal to allowsome control over the noise as well as provide some leeway, thus allowing themanipulation of the optical alignment without entirely losing the signal.

Figure 9: A photograph of the power supply settings.

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Figure 10: A photograph showing the electrical setup.

3.3 The phase quadrature pointAt this stage the voltage level is around 10 V, which is the optimal intensityof the detector. This is the maximum voltage possible without saturating thedetector and the detector is measuring a peak on the two dimensional intensitypattern. As explained previously, this prevents detection of angular velocitiesin both directions due to the voltage always decreasing regardless of how onerotates.

To allow angular velocities in both directions, an adjustment to the lenseslabelled 7, 10 and 11 in figure (1). What is needed is to find the phase quadraturepoint. One such point may be found, with its current calibration, by rotatingthe upper adjustment knob of the holder of lens 7 clockwise until the voltageintensity reaches 7.5 V. Then rotating the corresponding upper knob of 11counter clockwise until it is reduced by another 2.5 V to 5.0 V. Once this isdone, the lower knob of the detector, 10, will be moved counter clockwise sothat the signal reaches 3.3 V, a third of the initial strength. Now the voltagelevel should approximately move between 0.7 V and 5.9 V when the gyroscopeis rotated and stay at around 3.3 V when it is standing still.

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3.4 User interfaceThe design and functionality of the user interface is very important as it is themedium through which the user can be educated and interact with the gyro-scope. The main goals for the user interface are firstly, to display informativedata in real time, and secondly, to have a graphical response to the gyroscope’smotion.

The fundamental measured physical quantity is the angular velocity, so thisis important to show together with the output signal. From this, an angle froma reference point can be calculated. A user is allowed to arbitrarily change thisreference point, providing a valuable interaction where a user can examine thegyroscope in different situations and confirm that it works as intended.

Figure 11: Display of the functioning user interface.

A simple graphical model of the gyroscope is included in the user interfaceas it is educational to provide visual feedback that does not consist of numbers.Such an implementation allows a user to build a more intuitive understandingof how the measurement process functions.

In addition to the directly educational aspects of the interface, it also in-cludes calibration options. The calibration consists of finding the minimum andmaximum output signal, as these are essential parameters in the underlyingformulas used by the program.

3.4.1 Experimental evaluation

It is important that the angle rotated in the interface correctly corresponds tothe rotation in reality. The allowed range of angular velocities [-2.88, 2.88] de-

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grees per second has been incorporated in the program. Thus the highest andlowest voltage corresponds to the highest and lowest angular velocities respec-tively. Now a ninety degrees rotation of the gyroscope should correspond to afairly equal rotation in the interface. This range of angular velocities appear tobe valid for the translation of actual to virtual angular velocity. The experimen-tal tests yield that the rotation is almost equal, with an error of approximately2-3 degrees per 90 degrees. The error is most likely due to the difficulty topreserve angular velocities within the allowed interval for a longer period oftime.

3.5 Reduction of noiseThe optical alignment of the gyroscope is extremely sensitive and can be per-turbed by very small vibrations in its environment. These vibrations can beproduced by audible sound waves transmitted through the air, or by movementtransmitted through the ground in contact with the gyroscope’s support.

In order to reduce the noise caused by sound waves, the entire optical setupis surrounded by an acrylic glass shield. This significantly reduces the impactof stray sound as the intensity is dampened when passing through the shield.

Vibrations transmitted through the gyroscope’s support can be attenuatedby adding isolation material to the support. Therefore the gyroscope is sup-ported by air-filled plastic cushions and polystyrene foam.

Beyond shielding the optical setup from physical vibrations, it also possibleto reduce the noise of the output signal by manipulating the data. This isdone by accumulating values of the output signal over several time steps andaveraging over the time interval in an appropriate manner. The number of timesteps to be averaged over is somewhat arbitrary, for this implementation eachshown data point is an average of fifty values. This method is helpful in reducingany type of noise.

It is worth noting that for these methods to work well in reducing the noise,the acquisition rate of the data has to be very large. Therefore, in this imple-mentation, the acquisition rate is maximized. This means that the time step ishardware dependent, for the current system the time step is about 2 ms.

4 ResultsWhat has been created now is a fully functioning display with interface elementsshowing important information such as angular velocity, total angle moved,voltage output and current position. With a simple calibration of the outputsignal on the computer it seems to be translating voltage to angle correctly asthe display closely relates to the real life changes. This is of course, as long asone stays within the allowed range of angular velocities.

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5 AnalysisAlthough the gyroscope is functioning correctly and the display shows goodvalues there is always room for improvement. This includes reducing errors inthe calculations and adding more functions to the display and the gyroscope.These are also suggestions for future students who want to continue the workon this particular gyroscope.

5.1 Angular driftLooking at the running program, one may be able to see a slight drift in theangle. This is due to the fluctuations in the voltage output that are translated toangular velocity. Consequently the gyroscope will appear to rotate very slowlyon the screen while it is actually standing still. Adjustments that have alreadybeen made to account for this are, as mentioned before, firstly averaging theoutput values over intervals of fifty time steps in the program. Secondly reducingthe noise coming from the outside by encasing the gyroscope in acrylic glass andalso placing it on a noise-cancelling underlay.

Although these adjustments have been made, a small drift remains. Thisdrift is not crucial and the gyroscopes actual rotation is too large to be influencedby it. However, it may be of interest to remove it completely.

5.2 Further additionsSome addition to the gyroscope that may be useful for the demonstration arefirstly to make it able to detect the rotation of the earth. This can be done byadding a phase modulator to the optical setup. Using a specific frequency forthe modulator, significantly smaller angular velocities can be detected. Subse-quently one may also add functionality to the display to be able to show therotation of the earth as well.

Secondly, the rotational speed is limited by how the voltage acts as a functionof the phase shift. When a minimum or maximum is reached in figure (5), anincrease in the rotational speed will be indistinguishable from a decrease in therotational speed based on the voltage output. Thus some additional componentis required in order to measure the period order n of the signal. Several optionsexist for completing this task, one is to utilize an accelerometer to measure thecentripetal acceleration, and from this determine the order n. Another methodis to incorporate a second, low sensitivity, loop into the optical setup. Thesecond loop will not provide particularly accurate data, but the significantlywider range of detection is exploited in order to find the order n of the signalcreated by the first loop. Successfully implementing such a solution relieves theuser of restrictions concerning the angular velocity.

It may be of importance to also add an easy way to immobilize the gyroscopeso that it cannot rotate. First of all this enables easier calibrations as thegyroscope is not moving. Moreover, it also helps against small vibrations ordisturbances that causes unwanted rotation of the gyroscope.

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6 References[1] Corning. Corning® SMF-28™ Optical Fiber [Internet]. Issued: April 2002.Available from: http://ece466.groups.et.byu.net/notes/smf28.pdf

7 Appendix

7.1 ResponsibilitiesIf something should happen to the setup described in this report or if somethingis unclear please use the given email addresses. Emails should be sent to theperson with the ultimate responsibility for the section. Ola Sjölander has themain responsibility of the electrical setup and the visual interface while FransForsberg is mainly responsible for the optical setup and the calibration. Thecontact information is given on the title page.

7.2 LabVIEW version and licenseLabVIEW 2015 version 15.0.0, Windows version. License and software providedby KTH Student Software Distribution at https://www.kth.se/student/kth-it-support/software/download/labview/windows-1.572844. (May 16, 2016)

7.3 National Instruments driversNI-DAQmxBase 15.0.0 for NI USB-6009 device, Windows version. Provided byNational Instruments, download link: www.ni.com/download/ni-daqmx-base-15.0/5649/en/. (May 16, 2016)

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