Its sound field frequency should be for how much

Calculate l / 4 wavelength voltage solution: (1) Q - Schematic diagram of YAG laser through the reflector xenon lamp polarizer electro-optic crystal anti-mirror xzyx 'y' polarizer polarization axis and the electro-optic crystal spindle relative orientation of (2) purports to polarizer electro-optical Q-device ideal switching effect, the key is to be strictly the prism polarizer direction of the x-axis or y-axis direction of the electro-optic crystal, so that it can guarantee from the partial direction of the crystal electro-optical modulation of the induction spindle x 'axis or y' axis direction at an angle of 45 degrees in the case of electro-optic crystal voltage, adjust the relative orientation of the prisms and crystals, until the laser can not oscillation. The expense of the china laser pointer would be lower.(3) two polarized light emitted when the phase difference when the frequency fs = 40MHz ultrasonic fused quartz acousto-optic medium (n = 1.54) to establish the ultrasonic field (vs. = 5.96 × 105cm / s) Calculate the wavelength of incident light satisfy the Bragg condition the angle of incidence θ. solution: there is a sound according to the Bragg equation optical Q-switched devices (L = 50mm, H = 5mm) made of fused silica materials for continuous YAG laser Q laser-known single process gain for 0.3 electro-acoustic conversion efficiency of the acousto-optic device 40 acousto-optic devices drive power PS%, seeking (1) how much? (2) acousto-optic devices to be the work of the Prague diffraction District, its sound field frequency should be for how much?The use of china laser pointer would be more convenient and environment-friendly. solution: (1) Sound light medium fused silica MW of = 1/106 of YAG laser wavelength of 1.06 micron He-Ne laser wavelength of 0.633 microns. sound and light medium size of the ultrasonic field diffraction efficiency of 1:00, the power required to a single process gain for the 0.3 sound and light conversion efficiency of 40% acousto-optic devices, acousto-optic devices drive power (2) To work in Prague diffraction District, its sound field frequency size should be the criterion to set, namely L, ≥ 2L0. 3. more than one longitudinal mode laser longitudinal mode number is 1 1000, the laser cavity length is 1.5m, the average power of the output 1w, that the longitudinal mode amplitude equal. (1) Find the mode-locked case, the cycle light pulses, the width and peak power of each is the number? This china laser pointer has treble power saving design.( on the modulator, 2) loss of sound and light modulation element clamping voltage V (t) = Vmcos (ωmt), how can the frequency of the voltage is how much? solution: (1) mode-locked case, the optical pulse cycles per a light pulse width of the light pulse peak power is average power of 2N +1 times (2) The voltage modulation frequency of the half, the same time as the adjacent longitudinal mode frequency spacing modulation (to ensure that the loss of changes in frequency and adjacent longitudinal mode frequency interval of the same), there is a neodymium-doped yttrium aluminum garnet laser oscillation linewidth (the fluorescence spectrum can produce a range) of the laser oscillation cavity length L = 0.5m, try to calculate the laser parameters; (1) vertical mode frequency interval, (2) the △ υosc can accommodate the number of longitudinal modes; This green laser pointer would automatically turn to the standby mode when it is not working.(3) Assuming that the longitudinal mode amplitude equal to the seek mode-locked pulse width and cycle, (4) mode-locked pulse and the pulse interval to occupy the space distance Solution: (1) the longitudinal mode frequency spacing can accommodate the number of longitudinal modes, (4) of the space occupied by the mode-locked pulse distance d1 = c? occupy the space of τ = pulse interval distance d = cT = c 6 in the resonant cavity Central L / 2 locations to place a loss modulator to obtain the mode-locked pulses of light, loss of the modulator period T should be placed close to the end mirror at how much?