Modal Powers in a Multimode Laser. A He-Ne laser operating at λã= 632.8 nm produces 50 mW of multimode power at its output. It has an inhomogeneously broadened gain profile with a Doppler linewidth Î1b-1.5 GHz and the refractive index 1, The resonator is 30 cm long. (a) If the maximum small-signal gain coefficient is twice the loss coefficient, determine the 15.2.5 number of longitudinal modes of the laser. (b) If the mirrors are adjusted to maximize the intensity of the strongest mode, estimate its power.

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w