Question

The nearly parallel beam of a laser with wavelength λ = 10μm and output power of...

The nearly parallel beam of a laser with wavelength λ = 10μm and output power of P = 10 W has a beam diameter of d = 3 cm. It is focused by a lens with f = 20 cm. a) How large is the beam waist w0 in the focal plane? b) The intensity distribution in this plane is I(r) = I0 × exp[−(r/w0) 2] . What is the value of I0? c) Assume that 10% of the laser power can be used for evaporating material from a steel sheet with thickness t = 1 mm placed in the focal plane. How long will it take for the laser beam to produce a hole through the steel sheet, if the evaporation heat is 6 × 106 J/Kg

Homework Answers

Answer #1

a] Beam waist in the focal plane can be determined using Rayleigh's diffraction limit criteria.

this is the beam waist in the focal plane.

b] The intensity at this point is:

c] Power used up for evaporation = 10% of 10 W = 1 W

Radius of the hole =

thickness of the hole = 1 mm = 1 x 10-3 m

so, volume of the hole =

density of steel = 8050 kg/m3

therefore, mass of the steel evaporated = density x volume = 1.67295 x 10-7 kg

Energy required = mass x evaporation heat = 1.67295 x 10-7 x 6 x 106 = 1.00377 J

time = Energy / Power = 1.00377/1 = 1.00377s

this is how long it will take for the laser beam to produce the hole.

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A blue argon ion laser beam with power, P = 50 mW, and wavelength, λ =...
A blue argon ion laser beam with power, P = 50 mW, and wavelength, λ = 488 nm illuminates a white wall at a distance of 100 m. . The laser has a gaussian beam diameter of 700 µm at its output. The wall had a diffuse reflectivity of 0.1% per steradian. a. What is the laser beam diameter on the wall? b. What is the highest irradiance on the wall? c. What is the radiance of the scattered light?
A laser emits light at power 6.01 mW and wavelength 633 nm. The laser beam is...
A laser emits light at power 6.01 mW and wavelength 633 nm. The laser beam is focused (narrowed) until its diameter matches the 1060 nm diameter of a sphere placed in its path. The sphere is perfectly absorbing and has density 5.00 × 103 kg/m3. What are (a) the beam intensity at the sphere's location, (b) the radiation pressure on the sphere, (c) the magnitude of the corresponding force, and (d) the magnitude of the acceleration that force alone would...
A laser emits light at power 5.49 mW and wavelength 633 nm. The laser beam is...
A laser emits light at power 5.49 mW and wavelength 633 nm. The laser beam is focused (narrowed) until its diameter matches the 1230 nm diameter of a sphere placed in its path. The sphere is perfectly absorbing and has density 5.00 × 103 kg/m3. What are (a) the beam intensity at the sphere's location, (b) the radiation pressure on the sphere, (c) the magnitude of the corresponding force, and (d) the magnitude of the acceleration that force alone would...
A small laser emits light at power 6.88 mW and wavelength 441 nm. The laser beam...
A small laser emits light at power 6.88 mW and wavelength 441 nm. The laser beam is focused (narrowed) until its diameter matches the 1255 nm diameter of a sphere placed in its path. The sphere is perfectly absorbing and has density 4.00×103kg/m3. What is the beam intensity at the sphere's location? Calculate the radiation pressure on the sphere. Calculate the magnitude of the corresponding force. Calculate the magnitude of the acceleration that force alone would give the sphere?
A laser beam of diameter d1 = 1.4 mm is directed along the optical axis of...
A laser beam of diameter d1 = 1.4 mm is directed along the optical axis of a thin lens of focal length +5.1 cm (see figure below). (a) How far from the lens will the beam be focused? (b) A second positive lens is placed to the right of the first. Light emerges from the second lens in a parallel beam of diameter d2 = 3.5 mm. Thus the combination of lenses acts as a beam expander. Find the focal...
physics: optics q1: A 180 ?? laser produces a nearly parallel beam 20 ??2 in cross-sectional...
physics: optics q1: A 180 ?? laser produces a nearly parallel beam 20 ??2 in cross-sectional area at a wavelength of 710 ??. Determine the amplitude of the electric field in the beam, assuming the wavefronts are homogeneous and light travels in vacuum. q2: a) A light beam with an irradiance of 4 × 106 ?/?2 impinges normally on a surface that reflects 65.0% and absorbs 35.0%. Calculate the resulting radiation pressure on the surface. b)Compute the momentum of a...
Problem 6.1: Gaussian beam through a thin lens (5P) A collimated NeHe laser with wavelength ?...
Problem 6.1: Gaussian beam through a thin lens (5P) A collimated NeHe laser with wavelength ? = 633nm and beam diameter ? = 2mm is focused by a thin lens with focal length ? = 6mm. 10cm behind the thin lens is a spherical screen placed. The screen has the same curvature as the wave front at this position. The propagation direction of the beam is in z-direction and it’s ? = 0 at the lens’ position. (a) Draw a...
A fiber laser (? =1070 nm) with output power of 300 W is being used. The...
A fiber laser (? =1070 nm) with output power of 300 W is being used. The 1/e2 radius at the waist of the beam is 100 μm and is located at the surface of a substrate. 1. If the beam is Gaussian, what is the size of the beam 10 mm below the substrate? 2. If the beam has an M^2 value of 7.7, what is the size of the beam 10 mm below the substrate? 3. In terms of...
A typical small helium-neon laser (λ=632.8μm) has a continuous output power of 3.00mW and a beam...
A typical small helium-neon laser (λ=632.8μm) has a continuous output power of 3.00mW and a beam diameter of 2.00mm. a. What is the average value of the electric field's amplitude within the beam? b. How many photons are emitted each second by the laser?
an argon-ion laser(wavelength is 514.5nm, power is 1W) EMMIT A gaussian tem 00 beam with a...
an argon-ion laser(wavelength is 514.5nm, power is 1W) EMMIT A gaussian tem 00 beam with a minimum spot radium = 2mm, at z=0. What is the amplitude of the eletric field at the center of the beam, (r=0, z=0)? wht is the average of the eletric field amplitude?
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT