Question

A LASIK vision correction system uses a laser that emits 10 ns -long pulses of light,...

A LASIK vision correction system uses a laser that emits 10 ns -long pulses of light, each with 2.5 mJ of energy. The laser is focused to a 0.75 mm -diameter circle.

Part A- What is the average power of each laser pulse?

Part B-What is the electric field strength of the laser light at the focus point?

Express your answers using two significant figures.

Homework Answers

Answer #1

Solution:

Part A: Average power of a laser pulse depends on the pulse energy and the laser repetition rate.

=> Pavg = Energy * frequency

               = energy / time

Energy = 2.5 mJ = 2.5 e-3 J

t = 10ns= 10 e-9 s

=> Pavg = (2.5 e-3) / (10 e-9)

              = 2.5 e+5 watts

Part B:

Diameter = d = 0.75 mm

radius = r = 0.75/2 = 0.375 mm =0.375 e-3 m

Power / Area = Intensity (avg)

I avg = (2.5 e5 ) / (pi*0.375^2 e-6)

       = 5.66 e11 W

I peak = 2 * I avg = 2 * (5.66 e11)

                            = 1.13 e12 W

The electric field strength depends on the intensity and the impedence of free space.

=> sqrt(I peak Zo) = E

Zo= sqrt ( / = 376.73 ohms

Electric field strength = E= sqrt [ (1.13 e12)*(376.73) ]

    = 2.06 e7 V/m

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
LASIK eye surgery uses pulses of laser light to shave off tissue from the cornea, reshaping...
LASIK eye surgery uses pulses of laser light to shave off tissue from the cornea, reshaping it. A typical LASIK laser emits a 1.0-mm-diameter laser beam with a wavelength of 193 nm. Each laser pulse lasts 13 ns and contains 1.3 mJ of light energy. What is the power of one laser pulse? During the very brief time of the pulse, what is the intensity of the light wave?
A laser that emits pulses of UV lasting 2.95 ns has a beam diameter of 4.05...
A laser that emits pulses of UV lasting 2.95 ns has a beam diameter of 4.05 mm. If each burst contains an energy of 4.60 J, what is the length in space of each pulse? What is the average energy per unit volume (the energy density) in one of these pulses?
In laser eye surgery, the laser emits a 1.26-ns pulse focused on a spot that is...
In laser eye surgery, the laser emits a 1.26-ns pulse focused on a spot that is 37.0 μm in diameter. 1. If the energy contained in the pulse is 2.65 mJ , what is the power per square meter (the irradiance) associated with this beam? 2. Suppose a molecule with a diameter of 0.604 nm is irradiated by the laser beam. How much energy does the molecule receive in one pulse from the laser? (This much energy is likely to...
A high-energy pulsed laser emits a 1.0-ns-long pulse of average power 8.3×1011 W . The beam...
A high-energy pulsed laser emits a 1.0-ns-long pulse of average power 8.3×1011 W . The beam is 1.1×10?3m in radius. Part A Determine the energy delivered in each pulse. Express your answer using two significant figures. E =......?...... J Part B Determine the rms value of the electric field. Express your answer using two significant figures Erms = .....?...... V/m
A laser used in LASIK eye surgery produces 54.0 pulses per second. The wavelength is 193...
A laser used in LASIK eye surgery produces 54.0 pulses per second. The wavelength is 193 nm (in air), and each pulse lasts 10.0 ps. The average power emitted by the laser is 224.0 mW and the beam diameter is 0.800 mm. What is the total energy of a single pulse? What is the intensity during a pulse?
A high-energy pulsed laser emits a 1.0-ns-long pulse of average power 6.7×1011 W . The beam...
A high-energy pulsed laser emits a 1.0-ns-long pulse of average power 6.7×1011 W . The beam is 2.1×10−3m in radius. A) Determine the energy delivered in each pulse. (In J) B) Determine the rms value of the electric field. (In V/m)
A small helium-neon laser emits red visible light with a power of 5.90 mW in a...
A small helium-neon laser emits red visible light with a power of 5.90 mW in a beam that has a diameter of 2.60 mm . A)What is the amplitude of the electric field of the light? Express your answer with the appropriate units. B)What is the amplitude of the magnetic field of the light? C) What is the average energy density associated with the electric field? Express your answer with the appropriate units.
A laser emits 7.91 × 1018 photons per second in a beam of light that has...
A laser emits 7.91 × 1018 photons per second in a beam of light that has a diameter of 2.82 mm and a wavelength of 514.5 nm. Determine (a) the average electric field strength and (b) the average magnetic field strength for the electromagnetic wave that constitutes the beam. please help i will rate
A small helium-neon laser emits red visible light with a power of 5.90 mW in a...
A small helium-neon laser emits red visible light with a power of 5.90 mW in a beam that has a diameter of 2.10 mm . a) What is the amplitude of the electric field of the light? b) What is the amplitude of the magnetic field of the light? c) What is the average energy density associated with the electric field? d) What is the average energy density associated with the magnetic field? e) What is the total energy contained...
A typical helium-neon laser found in supermarket checkout scanners emits 633-nm-wavelength light in a 1.1-mm-diameter beam...
A typical helium-neon laser found in supermarket checkout scanners emits 633-nm-wavelength light in a 1.1-mm-diameter beam with a power of 1.3 mW . A) What's the amplitude of the oscillating electric field in the laser beam? B) What's the amplitude of the oscillating magnetic field in the laser beam?
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT