Quantizing Light: Photon Detection Spectrometers Quiz

If light passes through or reflects off a series of closely spaced slits (a grating), then the waves will overlap and interfere. If the constructive interference occurs at specific angles depending on the wavelength (λ), then the light will be spread into a spectrum. Therefore, the formation of a spectrum by a grating is a wave-related phenomenon.

If light were only a continuous wave, then a low-intensity beam would eventually provide enough energy to eject an electron after a long time. If experiments show that electrons are ejected instantly only if the light meets a frequency threshold, then light must arrive in discrete packets. Therefore, this proves the particle (photon) nature, making the statement false.

If a photon travels through the spectrometer, it exists in a state of probabilistic wave-like behavior. If it interacts with the detector material (like silicon), it is absorbed at a specific coordinate. If the interaction forces the photon to manifest at a single location, then the "wave" has collapsed into a particle-like detection event.

If De Broglie's hypothesis is correct, then every moving object has a wavelength. If h is Planck's constant and p is the product of mass and velocity, then the relationship is defined by the particle's momentum. Therefore, the answer is momentum.

If we treat light as a stream of particles (photons), then detection is a counting game. If not every photon that hits the sensor successfully creates an electronic signal, then we must know the ratio of success. Therefore, QE is the statistical measure of how well a sensor detects individual "particles" of light.

If energy is defined by E=hf, then energy and frequency are directly proportional. If the frequency (f) increases, then the energy (E) of the individual photon packet must also increase. Therefore, the statement is true.

If light enters a glass prism, its wave-speed changes. If different wavelengths (λ) change speed by different amounts, then they bend at different angles (dispersion). If this allows the "wave" to be separated into colors, then the refractive index is the governing wave property.

If light energy is not continuous but comes in "chunks," then each chunk is a quantum of light. If we are using a detector to count these chunks, then we are counting photons. Therefore, the answer is photon.

If an effect involves the bending, overlapping, or orientation of electromagnetic fields, then it is a wave property. If photoelectric emission involves the discrete "knocking" of electrons by packets of energy, it is a particle property. Therefore, A, B, D, and E are the wave-related options.

If we try to measure the wavelength (momentum) of a photon very precisely using a narrow slit, then the diffraction causes the photon's path to spread out (uncertainty in position). If narrowing one increases the spread of the other, then we are seeing Heisenberg's Uncertainty Principle in action. Therefore, it sets a fundamental limit on spectral resolution.

If a single photon hits the photocathode, it can eject one electron. If the dynodes in the PMT amplify that one electron into a large pulse of current, then the original single "particle" has been recorded. Therefore, PMTs are high-sensitivity particle detectors for light.

If more lines are present, then more "wavelets" interfere with each other. If more wavelets interfere, then the constructive peaks become narrower and more distinct. If the peaks are narrower, then we can distinguish between two very similar wavelengths. Therefore, it is an enhancement of wave interference.

If a photon hits a detector, it must have enough energy to overcome the binding force of the material. If this energy threshold is specific to the material used (like Silicon or Cesium), then it is called the work function. Therefore, the answer is function.

If a silicon atom absorbs a photon, the energy is transferred to an electron. If the energy is greater than the "band gap," then the electron becomes free to move (a charge carrier). If we collect these charges, we can measure the light intensity. Therefore, the particle-energy is converted into an electronic signal.

If a behavior involves counting, threshold energies, or "all-or-nothing" interactions, it is particle-like. If "shot noise" comes from the random arrival of individual photons and the "photoelectric effect" involves packet absorption, then they are particle behaviors. Therefore, A, B, and D are correct.

If p=h/λ, then momentum (p) is inversely proportional to wavelength (λ). If X-rays have much shorter wavelengths than visible light, then X-rays must have much higher momentum. Therefore, the statement is false.

If a high-energy photon hits an electron, it can "bounce" off like a billiard ball. If the photon changes direction and increases its wavelength (loses energy), it has behaved as a particle with momentum. Therefore, Compton scattering is a key proof of the particle nature of light.

If light can only be absorbed or emitted in specific "packets" of energy (hf), then it is not a smooth, infinitely divisible fluid. If we must treat it as a collection of individual units, then those units are discrete. Therefore, the answer is discrete.

If the grating uses wave interference to send different wavelengths to different physical pixels, then the "wave" part is doing the sorting. If the pixels then use the photoelectric effect to absorb and count photons, then the "particle" part is doing the measuring. Therefore, the system relies on both aspects of light to function.

If we send one photon at a time, we will see individual "dots" on the detector. If we wait and collect many such dots, then the dots will eventually build up the same interference pattern as a continuous wave. If this shows that each "particle" also has "wave" probabilities, then the statement is true.