Download final exam kérdések: 1.)There are n photons in a cavity composed of

final exam kérdések:
1.)There are n photons in a cavity composed of 2 parallel mirrors at d = … nm distance. Is it
true or false that..
a. Resonant frequencies of the cavity mode are f = … PHz
b. Energy of single photons in the corresponding cavity modes are E = … eV
c. if n1 photons are in the f1 PHz mode and n2 photons are in the f2 PHz mode
then the total electromagnetic energy in the cavity is E = … eV
d. if all photons are in the f1 PHz mode then the total energy in the cavity is
Etotal=....eV
e. if all photons are in the f2 PHz mode then the total energy in the cavity is
Etotal=....eV
2.)The monochromatic lambda=...nm wavelength, coherent stream of photons is moving into
the positive Z direction. The transmitted power is E0 pico watt. true or false?
a.) The energy of photon is about E1 eV
b.) The average number of photons are about N million photons/sec.
c.) If the signal is the average number of photons, the coherent noise level is E1 pico
watt, and the SNR is about A
d.)The direction of the momentum vector is -Z
e.)In case of a collision with a standing still hydrogen atom, the atom will gain a
velocity of about v=….m/s
3.
Physical observables are represented by linear self-adjoint operators
4.
The ratio of the number of electrons to the number of holes in an inter???(miez??)
semiconductor
5.
In an electron-gas (??) the distribution of electrons follows the Fermi-Dirac statistics
6.
Generation and Detection of Light is it true or false?
7.
The unperturbated system is a one-dimensional harmonic oscillator characterized by
its potential energy 0.5 Cx with C = … Ws/m . The system is perturbated by a timeindependent potential V(x) = 0 if x < 0.475 nm. V(x) = … eV if 0.475 < x < 0.525 nm; and V(x)
= 0 if 0.525 < x. We perform spectroscopic measurements on both the unperturbated and the
perturbated systems. True or false:
2
2
a.The ground state energy (vacuum fluctuation) is … eV.
b.The perturbation of the first excited (single photon) state changes the energy by
...eV.
c.The perturbation does not change the energy of the first excited state.
d.The unperturbated harmonic oscillator in its ground state would absorb a photon of
wavelength lambda = … nm.
e.The perturbated harmonic oscillator in its ground state could absorb a photon with
lambda = … nm.
8.
a
9.
a
10.
a
11.
a
12.
Fermi energy level of metals, dielectrics, intrinsic, n-type and p-type semiconductors.
true or false?
13.
a
14.
a
15.
a
16.
a
17.
a
18.
a
19.
Time-dependent perturbation of an ideal two-state quantum system by a close-to
resonance harmonic electromagnetic field. Is it true or false that…?
20.
Time-dependent perturbation of an ideal two-state quantum system by a close-to
resonance harmonic electromagnetic field pulse. Is it true or false that…?
21.
Rabi-oscillation of two-state atom. Is it true or false that…?
22.
Time-dependent perturbation of a quantum system by a close-to resonance harmonic
electromagnetic field pulse, in case of electron transition from a discrete level to an energy
band. Is it true or false that…?
23.
What do we know about photon absorption, spontaneous and stimulated emission?
Einstein coefficients. Is it true or false that…?
24.
The principle of Light Amplification by Stimulated Emission of Radiation (LASER). Is it
true or false that…?
25.
The p-n diode as light emitter (LED). Is it true or false that…?