/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q62P Ruby lasers are at a wavelength ... [FREE SOLUTION] | 91影视

91影视

Ruby lasers are at a wavelength of 694 nm. A certain ruby crystal has Cr ions (which are the atoms that lase). The lasing transition is between the first excited state and the ground state, and the output is a light pulse lasting 2.00渭蝉. As the pulse begins, 60.0% of the Cr ions are in the first excited state and the rest are in the ground state. What is the average power emitted during the pulse? (Hint:Don鈥檛 just ignore the ground-state ions.)

Short Answer

Expert verified

The average power emitted during the pulse is 1.1106W.

Step by step solution

01

The given data

The wavelength of the ruby lasers,=694nm

The output pulse last,t=2渭蝉

As the pulse begins, 60% are in a first excited state and 40% in the ground state.

Consider the known data as below.

Plank鈥檚 constant,h=6.6310-34Js

Speed of light,c=3108ms

02

Understanding the concept of average power and Plank’s relation:

The rate of energy flow in every pulse is called average power.

Photon energy is the energy carried by a single photon. The amount of energy is directly proportional to the magnetic frequency of the photon and thus, equally, equates to the wavelength of the wave. When the frequency of photons is high, its potential is high.

Using the equation of Plank's relation, to get the energy of the photon that is being emitted by the laser. Now, using this value in the power equation considering the criteria of emitted photons, to find the average power of the emitted pulse.

Formulas:

The energy of the photon due to Planck鈥檚 relation,

E=hc 鈥.. (1)

The average power of the emitted pulse is,

Pavg=(N1-N2)Ephotont 鈥.. (2)

03

Calculation of the average power:

At first, the energy of the photon is calculated using the given data in equation (1) as follows:

E=6.6310-34J.s3108m/s69410-9m=2.8710-19J

Now, according to the problem consider the known data due to the absorption of the emitted photons of the Cr ions in the excited state by the ions in the ground state.as below.

The number of atoms in the excited state,N1=0.6 and

The number of atoms in the ground state, N2=0.4

Thus, the average power emitted during the pulse is given using equation (2) and, the given data is as follows.

Pavg=0.6-0.42.871019J0.210-6s=1.1106J/s=1.1106W

Hence, the value of the average power is 1.1106W.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

On which quantum numbers does the energy of an electron depend in (a) a hydrogen atom and

(b) a vanadium atom?

In an NMR experiment, the RF source oscillates at 34 MHz and magnetic resonance of the hydrogen atoms in the sample being investigated occurs when the external field Bexthas magnitude 0.78 T . Assume that Bintand Bext are in the same direction and take the proton magnetic moment component zto be1.410-26J/T . What is the magnitude of Bint?

A hypothetical atom has two energy levels, with a transition wavelength between them of . In a particular sample at 300 K,4.01020such atoms are in a state of lower energy. (a) How many atoms are in the upper state, assuming conditions of thermal equilibrium? (b) Suppose, instead, that3.0x1020 of these atoms are 鈥減umped鈥 into the upper state by an external process, with1.01020 atoms remaining in the lower state. What is the maximum energy that could be released by the atoms in a single laser pulse if each atom jumps once between those two states (either via absorption or via stimulated emission)?

Which (if any) of the following are essential for laser action to occur between two energy levels of an atom?

(a) There are more atoms in the upper level than in the lower.

(b) The upper level is metastable.

(c) The lower level is metastable.

(d) The lower level is the ground state of the atom.

(e) The lasing medium is a gas.

How many electron states are there in the following shells: (a) n = 4 , (b) n = 1 , (c) n = 3 , (d) n = 2 ?

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.