0 Members and 1 Guest are viewing this topic.
Interference pattern built up photon by photonQuoteThis movie has been captured with an intensified CCD camera. The movie consists of 200 frames, with exposure times ranging between 0,025 milliseconds and 6,000 milliseconds. It shows how individual photons, transmitted through a double slit, form an interference pattern. It shows wave-particle duality of light.Does anyone notice that the bright spots have various brightness? How should we interpret it?Moreover, what is the size of the photons producing that bright spots?Do they depend on their frequency?Do they depend on their polarization?
Boy, Was I Wrong! How the Delayed Choice Quantum Eraser Really works
Moreover, what is the size of the photons producing that bright spots?Do they depend on their frequency?Do they depend on their polarization?
Quote from: hamdani yusuf on 04/11/2023 08:19:33Moreover, what is the size of the photons producing that bright spots?Do they depend on their frequency?Do they depend on their polarization?Not sure what you mean by "size" of a photon. SInce there is a clear interference pattern. the photons will all have had pretty much the same frequency/wavelength/energy.
What determined the diameter of those bright spots on the screen in those single photon double slit experiments?
If the frequency of the light source is doubled, would it change the diameter of those bright spots?
The pictures I posted here are screenshots of my next videos. The first will show a closer look to the phenomenon, while the second one tries to offer some explanations. The existence of several effects at once in a single piece of evidence may prevent us from identifying the phenomenon in the first place. I'd like to have some constructive feedback to improve my videos before uploading them. Does anyone notice some unusual effects I haven't mentioned yet? Or think that the effects I did mention here implausible?
Quote from: hamdani yusuf on 04/11/2023 11:29:53What determined the diameter of those bright spots on the screen in those single photon double slit experiments?See reply #257 above.Quote from: hamdani yusuf on 04/11/2023 11:29:53If the frequency of the light source is doubled, would it change the diameter of those bright spots?Generally, yes, because each interaction with the primary detector will release twice as much energy, either in the form of visible photons or electrons depending on the incident radiation and the type of detector used. Most likely electrons.
https://www.tedpella.com/cameras_html/ccd_cmos.aspxFigure 1: Diagram of a CCD.On a CCD, most functions take place on the camera's printed circuit board. If the application's demands change, a designer can change the electronics without redesigning the imager.Figure 2: Diagram of a CMOS.A CMOS imager converts charge to voltage at the pixel, and most functions are integrated into the chip. This makes imager functions less flexible but, for applications in rugged environments, a CMOS camera can be more reliable.This difference in readout techniques has significant implications for sensor capabilities and limitations. Eight attributes characterize image sensor performance.Responsivity, the amount of signal the sensor delivers per unit of input optical energy. CMOS imagers are marginally superior to CCDs.Dynamic range, the ratio of a pixel's saturation level to its signal threshold. CCDs have the advantage here.Uniformity, is the consistency of response for different pixels under identical illumination conditions. CMOS imagers were traditionally much worse than CCDs, however new amplifiers have made the illuminated uniformity of some CMOS imagers close to that of CCDs.Shuttering, the ability to start and stop exposure arbitrarly, is superior in CCD devices. CMOS devices require extra transistors or nonuniform shuttering, sometimes called rolling shuttering to achieve the same results.Speed, an area in which CMOS arguably has the advantage over CCDs because all of the camera functions can be placed on the image sensor.Windowing, CMOS technology has the ability to read out a portion of the image sensor allowing elevated frame rates for small regions of interest. CCDs generally have limited abilities in windowing.Antiblooming, is the ability to gracefully drain localized overexposure without compromising the rest of the image in the sensor. CMOS generally has natural blooming immunity. CCDs require specific engineering to achieve this capability.Biasing and clocking. CMOS imagers have a clear advantage in the area, operating on a single bias voltage and clock level.CCD and CMOS imagers were both invented in the late 1960's. CCD became dominant in the market, primarily because they produced superior images with the fabrication technology available. CMOS image sensors required more uniformity and smaller features than silicon wafer foundries could deliver at the time. Not until the 1990's, with the development of lithography was there a renewed interest in CMOS. That interest is due to lower power consumption, camera-on-a-chip integration, and lowered fabrication costs. Both CCD and CMOS imagers offer excellent imaging performance. CMOS imagers offer more integration (more functions on the chip), lower power dissipation (at the chip level), and the possibility of smaller system size.Today there is no clear line dividing the types of applications each can serve. CCD and CMOS technologies are used interchangeably. CMOS designers have devoted intense effort to achieving high image quality, while CCD designers have lowered their power requirements and their pixel sizes. As a result, you can find CMOS sensors in high-performance professional and industrial cameras and CCDs in low cost low power cell phone cameras. For the moment, CCDs and CMOS remain complementary technologies-one can do things uniquely the other cannot. Over time this distinction will soften, with more CMOS imagers consuming more and more of the CCD's traditional applications. Considering the relative strength and opportunities of CCD and CMOS imagers, the choice continues to depend on the application and the vendor more than the technology.
Quote from: alancalverd on 05/11/2023 10:34:36Quote from: hamdani yusuf on 04/11/2023 11:29:53What determined the diameter of those bright spots on the screen in those single photon double slit experiments?See reply #257 above.Quote from: hamdani yusuf on 04/11/2023 11:29:53If the frequency of the light source is doubled, would it change the diameter of those bright spots?Generally, yes, because each interaction with the primary detector will release twice as much energy, either in the form of visible photons or electrons depending on the incident radiation and the type of detector used. Most likely electrons.
How do you think the double in size of the bright spots come out?
Quote from: hamdani yusuf on 06/11/2023 13:17:20How do you think the double in size of the bright spots come out?Scatter within the CCD, scatter within the intensifier, and halo from the optics, are the usual causes.
See reply #264, second part.
Yes, and the bright spots are larger than the pixels.
Activating two pixels at once will make the bright spot elongated.
What would happen if the photon frequency is only 50% higher than before?
The spots you can see on the image almost certainly span more than two pixels.
You get 50% more energy deposited in the first interaction.
In quantum mechanics, wave function collapse occurs when a wave function?initially in a superposition of several eigenstates?reduces to a single eigenstate due to interaction with the external world.https://en.m.wikipedia.org/wiki/Wave_function_collapse
Quote from: alancalverd on 09/11/2023 17:35:10The spots you can see on the image almost certainly span more than two pixels.What happens in case of less than two pixels?
Quote from: alancalverd on 09/11/2023 17:35:10You get 50% more energy deposited in the first interaction.In what form?
You get a very tiny dot in the display
QuoteIn quantum mechanics, wave function collapse occurs when a wave function?initially in a superposition of several eigenstates?reduces to a single eigenstate due to interaction with the external world.https://en.m.wikipedia.org/wiki/Wave_function_collapse In various experiments using dim light source, the wave function doesn't seem to collapse when it interacts with many kinds of objects such as mirrors, lens, polarizers, slits, gratings, quarter wave plates, half wave plates, air molecules, and beam splitters. Only certain kinds of objects can cause the wave function to collapse, such as electronic photosensors. There must be something that causes that difference in behavior.
History and contextThe concept of wavefunction collapse was introduced by Werner Heisenberg in his 1927 paper on the uncertainty principle, "?ber den anschaulichen Inhalt der quantentheoretischen Kinematik und Mechanik", and incorporated into the mathematical formulation of quantum mechanics by John von Neumann, in his 1932 treatise Mathematische Grundlagen der Quantenmechanik.[10] Heisenberg did not try to specify exactly what the collapse of the wavefunction meant. However, he emphasized that it should not be understood as a physical process.[11] Niels Bohr also repeatedly cautioned that we must give up a "pictorial representation", and perhaps also interpreted collapse as a formal, not physical, process.[12]Consistent with Heisenberg, von Neumann postulated that there were two processes of wave function change:The probabilistic, non-unitary, non-local, discontinuous change brought about by observation and measurement, as outlined above.The deterministic, unitary, continuous time evolution of an isolated system that obeys the Schr?dinger equation (or a relativistic equivalent, i.e. the Dirac equation).In general, quantum systems exist in superpositions of those basis states that most closely correspond to classical descriptions, and, in the absence of measurement, evolve according to the Schr?dinger equation. However, when a measurement is made, the wave function collapses?from an observer's perspective?to just one of the basis states, and the property being measured uniquely acquires the eigenvalue of that particular state, λ. After the collapse, the system again evolves according to the Schr?dinger equation.