Skip to main content

Characteristics, Advantages, Disadvantages and Applications of Ruby Laser

Characteristics of Ruby Laser →

Some of the characteristics of ruby laser are given as follows:

  1. Ruby laser is the first working laser that was developed in 1960.

  2. Ruby lasers are three-level solid-state pulsed lasers with pulse lengths of the order of a millisecond.

  3. This laser uses a synthetic Ruby crystal that is Aluminium oxide as its gain medium.

  4. A triply ionized chromium $$Cr^{+3} is used as a dopant for active ion, concentration bring of the order of $0.055%$.

  5. Ruby crystals are hard and durable, chemically stable and it has good thermal conductivity.

  6. Ruby lasers are optically pumped using a flash lamp.

  7. In a ruby laser, water or liquid nitrogen is used as a coolant.

  8. These lasers produce pulses of visible light at wavelength $6928A^{\circ}$ and $6943A^{\circ}$, with $6943A^{\circ}$ as dominant wavelength which is a deep red color.

  9. Ruby laser is highly temperature-dependent.

  10. A practical ruby laser operates at about $1%$ efficiency.

  11. Pulse repetition rate is comparatively low, of the order of $1$ to $2$ pulse per second.


The Advantages of Ruby Laser →

Some advantages of ruby laser are mentioned below:

  1. Ruby laser is very easy to construct and operate.

  2. A very strong and intense laser beam up to an output power of $10^{4}- 10^{6} W$, is generated in this laser.

  3. It has a degree of coherence.

  4. Ruby crystal is hard, durable and it has good thermal conductivity and coherence length.

  5. It is chemically very stable.

  6. The laser crystal can be grown with a high degree of optical quality.


The disadvantage of Ruby Laser →

Following are some disadvantages of Ruby laser:

  1. Ruby cannot be grown in large dimensions.

  2. Ruby laser is less directional and has very small efficiency.

  3. High excitation energy is required as more than half of the active centers are to be excited to achieve population inversion

  4. It has a very small operation for only a few hours.

  5. producers pulsed output of microsecond duration($\approx30 \mu s$).

  6. Very high heat is produced in these lasers due to which an effective cooling system is required.

  7. In these lasers, only a small part of pumping power is utilized in the excitation of chromium ion $Cr^{+3}$ and the rest goes to heat up to apparatus.


Applications of Ruby Laser →

Ruby laser have declined in use with the discovery of a better lasing medium but they are still used in a number of applications some of which are given as follows:

  1. These lasers are used in optical holography to produce holographic portraits, in size up to a meter square.

  2. These lasers are used in tattoo and hair removal but are being replaced by other lasers.

  3. These lasers are used in the measurement of plasma properties such as electron density temperature etc.

  4. These lasers are used where short pulses of red light are required.

  5. These lasers are used in labs to create holograms of large objects such as aircraft tires to look for weaknesses in the lining.


Spiking in Ruby Laser →
Spiking in Ruby Laser
Spiking in Ruby Laser

Ruby laser is a three-level pulsed laser. The operation of ruby laser leads to a pulsed output with flash lamps as pumping source. The output of a ruby laser is found to consist of a series of pulses of duration of a microsecond or less. The output of this laser is a highly irregular function of time with the intensity having random amplitude fluctuation of varying duration as shown in the figure. These pulses of the short duration are called spikes and the phenomenon is called laser spiking. Duration of individual spikes is of the order of $0.1-1 \mu s$, the time interval between two adjacent spikes is about $1-10 \mu s$. The power of each spike is of the order of $10^{4}- 10^{5} W$. The characteristic spiking of ruby laser

The Characteristic Spiking of Ruby Laser →

When the pumping source (flash lamp) is turned on the population at the upper level gradually increases while the population at the lower energy level decreases. The duration of the exciting flashlight is of the order of milliseconds and may be sufficiently intense to build up population inversion very rapidly. As soon as the population at the upper level becomes sufficiently large and the threshold condition is reached, laser action starts producing a laser pulse. Due to laser pulsed emission population of upper laser level is depleted more rapidly than it can be restored by flashlight. This process leads to leads to an interruption of laser oscillations, the laser oscillation ceases for a few microseconds. Because the flash lamp is still active it again builds up population inversion and laser oscillations beings causing other spikes and the sequence is repeated. A series of pulses is thus produced itself till the intensity of the flashlight has fallen below the threshold value due to which it is not possible to rebuild the necessary population inversion and the lasing action stops.
Labels:

Comments

Post a Comment

If you have any doubt. Please let me know.

Popular Posts

Numerical Aperture and Acceptance Angle of the Optical Fibre

Angle of Acceptance → If incident angle of light on the core for which the incident angle on the core-cladding interface equals the critical angle then incident angle of light on the core is called the "Angle of Acceptance. Transmission of light when the incident angle is equal to the acceptance angle If the incident angle is greater than the acceptance angle i.e. $\theta_{i}>\theta_{0}$ then the angle of incidence on the core-cladding interface will be less than the critical angle due to which part of the incident light is transmitted into cladding as shown in the figure below Transmission of light when the incident angle is greater than the acceptance angle If the incident angle is less than the acceptance angle i.e. $\theta_{i}<\theta_{0}$ then the angle of incidence on the core-cladding interface will be greater than the critical angle for which total internal reflection takes place inside the core. As shown in the figure below Transmission of lig
Post a Comment
click here »

Fraunhofer diffraction due to a single slit

Let $S$ be a point monochromatic source of light of wavelength $\lambda$ placed at the focus of collimating lens $L_{1}$. The light beam is incident normally from $S$ on a narrow slit $AB$ of width $e$ and is diffracted from it. The diffracted beam is focused at the screen $XY$ by another converging lens $L_{2}$. The diffraction pattern having a central bright band followed by an alternative dark and bright band of decreasing intensity on both sides is obtained. Analytical Explanation: The light from the source $S$ is incident as a plane wavefront on the slit $AB$. According to Huygens's wave theory, every point in $AB$ sends out secondary waves in all directions. The undeviated ray from $AB$ is focused at $C$ on the screen by the lens $L_{2}$ while the rays diffracted through an angle $\theta$ are focussed at point $p$ on the screen. The rays from the ends $A$ and $B$ reach $C$ in the same phase and hence the intensity is maximum. Fraunhofer diffraction due to
Post a Comment
click here »

Particle in one dimensional box (Infinite Potential Well)

Let us consider a particle of mass $m$ that is confined to one-dimensional region $0 \leq x \leq L$ or the particle is restricted to move along the $x$-axis between $x=0$ and $x=L$. Let the particle can move freely in either direction, between $x=0$ and $x=L$. The endpoints of the region behave as ideally reflecting barriers so that the particle can not leave the region. A potential energy function $V(x)$ for this situation is shown in the figure below. Particle in One-Dimensional Box(Infinite Potential Well) The potential energy inside the one -dimensional box can be represented as $\begin{Bmatrix} V(x)=0 &for \: 0\leq x \leq L \\ V(x)=\infty & for \: 0> x > L \\ \end{Bmatrix}$ $\frac{d^{2} \psi(x)}{d x^{2}}+\frac{2m}{\hbar^{2}}(E-V)\psi(x)=0 \qquad(1)$ If the particle is free in a one-dimensional box, Schrodinger's wave equation can be written as: $\frac{d^{2} \psi(x)}{d x^{2}}+\frac{2mE}{\hbar^{2}}\psi(x)=0$ $\frac{d^{2} \psi(x)}{d x
Post a Comment
click here »