People should buy a led flash light with good after service

We can see from the above: the E2 and E4; E3 and E4; E2 and E3 levels occurred between the particles inversion. 7 a homogeneous material light absorption coefficient 0.01mm-1, the light of the material by 10cm long, the outgoing light intensity of incident light intensity of a few percent? (2) If a beam of light through the length of 1M incentive to work even matter, if the incident radiation intensity is twice as strong and try to find the material gain coefficient. Solution: Let the light into the material for the first I0, after z is the distance light after the I (z), according to the definition of loss coefficient can be obtained: the emitted light intensity and the percentage of incident light:People should buy a green laser pointer with perfect stability. According to the small signal gain factor concept: g 0 = In the case of small-signal gain, the above equation can be obtained by integration: A Glossary and essays for a longitudinal cavity mode spacing and the expression of two adjacent longitudinal modes of the frequency difference △ vq called the longitudinal mode spacing. (L 'of the optical cavity length) (2) the type of optical cavity loss type geometric loss of light deflection cavity loss, diffraction loss, incomplete endoscopic reflection loss caused by the material in the non-activated absorption, scattering, etc. 3 write the spherical lens, thin lens, the natural spread of the transformation matrix to write a spherical mirror, spherical mirror write thin lens, spherical lens of the transformation matrix to write the stability of coaxial spherical cavity conditions, and write a brief description of the stability of coaxial spherical cavity conditions, write coaxial spherical cavity, People should buy a led flash light with good after service.the stability condition requires next to the axis of the light conditions and from any time in the chamber without lateral escape cavity, then the transformation matrix Tn several times from the various elements of An, Bn, Cn, Dn For any value of n are limited, and as n increases cyclical changes occur, then rn, θn also occurs as n increases cyclical changes, but rn, θn remain limited. 5 Since the reproduction mode to begin to speak from the reproduction mode on the mirror can be reproduced by a departure from the stable field distribution formed and began the phenomenon known as self-reproduction mode. 6 square mirrors on the fundamental mode amplitude distribution of the expressions in the mirror and characteristics of square mirrors on the fundamental mode amplitude distribution of the expressions in the mirror and characteristics of the field distribution function TEM00: fundamental mode amplitude from the lens center to the edge of the smooth landing. Select the green laser pointer by checking if the receiver of it contacts well.7 round square mirrors on the fundamental mode amplitude distribution of the expressions in the mirror and characteristics of circular TEM00 field distribution function: the mirror on the fundamental mode amplitude distribution is Gaussian, the entire section of the mirror there is no field line. 8 mode volume of a model to describe the mode volume of the cavity mode in the range of room for expansion. 9 far-field beam divergence angle is defined as the radius of the hyperbolic angle between two asymptotes. Try to prove that the cavity is stable cavity, find its equivalent confocal cavity parameters, in the graph is equivalent to the specific location of a confocal cavity. When select a green laser pointer, remember to test how far it can remote control practically.Solution: coaxial spherical cavity stability discriminant formula? 1 <1 (A + D) <1, this formula is universal (material 362 text of the middle of the page).