the strict and perfect parameter and technology of green laser pointer
When the optical trap red detuning (Δ <0), the optical dipole potential for the attractive potential, the atoms are attracted to the light intensity the strongest at, such as atoms was imprisoned in the standing wave field antinodes at; and when the optical trap blue loss harmonic (Δ> 0), the optical dipole potential for the repulsive atom is repulsion to light the strength of Office, such as atoms was imprisoned in the standing wave field section at. Experiment often used hollow beam trap, the blue shift of the atomic capture the intensity of the hollow beam smaller at. Red-detuned focusing Gaussian beam atomic imprisoned advantage of easy access to the Gaussian beam optical trap is easy to implement, high laser power, atomic load easily. But there are also disadvantages, such as the focused spot size, the atomic density is low; in the same power and detuning conditions, the high rate of photon scattering, atomic short life. The pen shape laser pointer pen is very easy and convenient for the customer.
Cavity single atom optical dipole trap confinement principles and programs relative to free space in the traveling-wave trap (such as focusing the Gaussian optical trap) in the cavity to form the standing wave trap scale is small, only orders of magnitude in wavelength. In the one-dimensional standing wave dipole trap formed by the micro-cavity along the cavity axis direction, the light intensity in the wavelength scale periodic changes in the smaller, conducive to the formation of larger gradient, and thus have a stronger dipole capture the role. In particular, in the same input laser power, high-precision micro-cavity light field due to the resonance-enhanced cavity light intensity density is greatly improved, and thus the dipole trap depth of the cavity can be much larger than free space optical trap depth. It is due to the strict and perfect parameter and technology of laser pointer .
In a high-finesse optical cavity, due to the strong coupling of the atom and cavity field, the exchange between the atom and cavity field photon, the role of light on the atomic force is completely different from the free space. However, the high-finesse optical microcavity laser frequency drift, as well as micro-cavity cavity vibration is extremely sensitive to tiny perturbations can also cause the cavity light field of a significant change, thus affecting the intracavity dipole trap. As the detuning increases, the intracavity power drastically reduced, and the dipole trap potential well depth is also reduced. Moreover, the rate of decay of dipole trap with the finesse of the cavity: the greater the granularity, the cavity field is more sensitive to the detuning. In order to maintain the well depth of potential well changes not less than half of the original well depth, the change of cavity length should be less than 10-3 nm, which strict experimental control of the microcavity. The safety lock of green laser pointer can ensure the safety and security of the customer.
Do not use a high-finesse cavity, and even free space in the dipole trap experiment, will not encounter such difficulties. Laser linewidth dipole trap well depth of - 11 - East China University of Technology thesis single-atom laser imprisoned: With the increase in other frequency components in the optical field, the composition of the resonance cavity light field can reduce the cavity intensity density decreases, the dipole trap potential well depth is gradually reduced. Therefore, in order to even Aurora valid input cavity, the laser linewidth should be narrow. Comparatively speaking, the higher the finesse of the cavity, the trap on the line width change, the more sensitive. For a ground state g and excited state e transition frequency for of ωα the two-level atom. The design of wireless 200mw laser pointer has been improved.