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COLLEGE Prysics L Chapter fi ee Optics: ' Optics is the branch of Physics which deals with the propage Optics can be subdivided into two major areas: i physical optics a) Geometrical optics | ; Geometrical Optics: jows of reflection and refraction of light in the “This area of optical science concerns the applicat jon of Io instruments.” ; ; polarization of light, interfe e study of the ents of do not indicate whether light lenses and other optical compon Physical Optics: “The physical optics concerns nature diffraction of fight.” e Interference a longitudinal or tra nsvi Polarization of light in Physical optics, with refe of light and th light but nd diffraction confirm the wave nature of lig erse. dicates that light waves are tra rence to polarization, stu wt waves and their inte erse in nature vshaviout of \igh nsv! dies the 6 if electromagnetic wave matter. exercise Long Question} Define the phenomenon © classify the polarization of wav joes polarization oO f polarization of waves. How di eS» hen the light is said to be pol only in one plane, “Uf the light hi phenomenon is called Polariza’ tion.” string, particle vibrations Transverse Mechanical Waves | waves, such as those on a eeesnes In transverse mechanica occur perpendicular to the wave's direction of propagation These vibrations can be oriented vertically, horizontally, or in any direction. Such waves are said to be polarized. The plane of polarization is defined as the plane containing both thi vibration and the direction of wave propagation. rf V4) e direction of particle 0 ( Structure of Light Waves: A light wave, generated by an oscillating charge, consists of a periodic variation of the electric field vector E and the magnetic field vector B ies ema og to each other. , + ctors are _ picwndiroe are also perpendicular to the direction of wave | fr Unpolarized Light 2 “CE <4 1 Ordinary _ consists of electric field vibrations in all poss ble planes perpendicular to the direction of propagation Such light is referred to as unpolarized. icti lectric an ic vi " Wh pe process of restricting the electric and magnetic vibrations of light to a (ce waves can be polarized, such as light. sver yes donot exhibit polarization, such as sound. wal Becomes Polarized? larized by the following methods: g filter (e-8, polaroid sheet). ™ b ha polarizin nasi olarizing beam splitter. } — ysin ing certain optical crystals or materials (e.g., calcite, quartz, = e involves using a polarizing filter such as a polarizing beam splitter or a pola asses through the polarized filter, only that electric field vector which is p: t, while all other vectors are blocked. y ach common technidu eos un olarized light P ed filter can pass through i ht then becomes polarized. of transforming unpolarize by natural phenomena like je! : 1 so olariz! t lig resultan The The process jarized d light into polarized light is known as polarization. reflection, refraction and scattering. gran alo be pol Multiple Choice Questions \ into one plane of vibration is called: ce Confinement of light 4 (a) Diffraction (b) Interference (c) Polarization (a) Dis 1 which of the following is an example of unpolarized light? a) Light from a laser - b) Light from a ccndis . d) Light from a TV screen c) Light through a Polaroid What characterizes unpolariz a} Vibrations in a single plane ¢)No electric field component 4, Howis unpolarized light typically polarized? a) By passing through a polaroid sheet ¢} By splitting it into colors 5, Which material can polarize light w _ 2) Glass b) Metal 6.” What happens when unpolarized light pas a) All vibrations are blocked , ¢) Light becomes unpolarized | Ordinary light can be plain polarized by the process of (a) scattering (c) Refraction through crystals ed light? b) Vibrations in all planes d) Constant intensity b) By increasing its intensity d) By reflecting it off water hen unpolarized light passes through it? c) Calcite ses through a polarizing filter? b) Only one plane of vibration pa d) Light intensity doubles a) (b) reflection from different sur (d) all of the above ECTION g vn) om an polaried ment obtained by us from 2 plane sheet of gi, flection r ass, yY THE ‘upon pe for elas) the reflected light b, In 1808, Malus distovered that ordinary unt beco™hs aa va © When unpolarized light strikes @ glass sul polarized. * - If this reflected light is viewe about the line of vision, light’s inten: © Light is extinguished at 2 partic laroid. ° This observation proves that the light refle glass is practically plane po! Example: Light reflected from the surface of a table aagit viewed through a rotated polaroid, showing tha plane polarized. smooth surface of water is partially Light reflected from SI polarized parallel to the surface. Ray Diagram th, rface at 2 5 i id J through 2 rotating polaro! sity varies. ular position of the cted by the larized. es darker when it is partially ¥ Etienne-Louis Male Multiple Choice Questions | glass plane polarized? At what angle is light reflected from c) 45° a) 90° _ b) 57° d) 30° polarizing angle? b) It becomes plane polarized d) It changes wavelength What happens to reflected light at the a) It becomes unpdlarized c) It is fully absorbed How can you confirm reflected light is polarized? a) Rotate a polaroid and observe dimming b) Measure its speed ¢) Split it with a prism ‘ d) Increase its intensity = =a a ICS} CamScanner - REED CHO. L PHYSICAL OPTICS & GRAVITATIONAL WAVES Pee a Pr ; / q aad ‘angle of incidence on a transparent medium when the reflected light is almost plane polarized is called the mer angle. we of unpolarized light be made incident on the surface of medium 2. ; et? it ed beam of light is almost plane polarized, the reflected and refracted beams are at right angle to each ‘ wor the polarizing angle, i=0, 4 0, +0, =90° 0, =90" -6, slaw, sels nsinO, =n,sind, tof
| 2. Imaging and Microscopy sng glare (unwanted light that interferes with vision) % Polarization enhances image quality, cars fae ging: m,, contrast, especially in microscopy and me’ leveraging i 4 3. Medical Applications “tissue imaging, and laser surgery, leveraBing Its abiliny Polarization is used in cancer diagnosis, Sisg, between different tissue types- f light fi di a 4, Astronomy i Jarization of light from istant . ena, lik the Po Stars Polarization helps us to analyze cosmic phenom °F the i microwave background radiation. | 5 fields speh as optics and photonics, imaging and i 5. Miscellaneous Fields a coe Polarization has importance in miscellaneou: tion system, etc. biology and chemistry, communica’ Two Main Applications of Polarization iw Polarizers, also known as polarizing filters, have two main app ic 3 1, Sky Photography oan © Acamera fitted with a polaroid (polarizing filter) captures polarized lent from the sty. © Polarizers reduce glare and haze caused by light scattering from @ ‘mosp! particles and molecules. , ; «They enhance contrast by blocking excessive bright fight and allowing other colours to pass. ; thus improving overall image quality. This results in brighter, detailed images, 2. Stress Analysis of Materials mo a ; Polarizers are used in materials science to analyze stress and strain in materials like plastics, metals, and glass affecting its interaction with polarized light and forming i Mterty a ey Mechanism: Stress alters a material's molecular structure, patterns or fringes. tterns provide qualitative data about the material. These interference pa Photoelasticity Technique h transparent materials and analyzing changes in 7 By shining polarized light throug polarization, researchers can: i. Determine stress patterns in the material li, Identify potential weaknesses or defects iif, Analyze the material's optical properties iv, Understand the material’s behavior under various conditions This technique is widely applied In engineering, materials science, and quality control. Polarizers are essential for manipulating light to achieve goals like enhancing image quality or analyzing nz properties. [SOLVED EXAMPLES — 8.2 — Find the refractive Index of a medium If polarizing inaie Is 54,5", So: 6, = 54,5° n=? tan6, =n n=tan 9, =tan54,5° =1,4 SICAL OPTIC TA CHA#B | PHY tar COLLEGE PHySics 11™ PUNJAB | 306 ee a. - ‘ i, orfuhite a such as black holes, neutron stars, warfs, Orbitin 0 cay, ~ E Kh Binary Systems and GWs ; A binary system consists of two compact objects, SUC | waves, and their mergers (collision and and emitting gravitational waves. piers sn lagi! Sahoo linet aan perisetey eonere among the most intense cosmic events, n i je ol + assive objects resulting more massive sin f merger dynamics, offering ing: ° The ma information about the system's mass, spin, and ger ey M8 insights int, extreme cosmic objects. : they emit gravitational waves, whic " inaries) orbit each other; they » Which can The binary systems (also termed as bina a Gravitational wave Observatory, USA) and Ving be ge by observatories like UGO- (Laser Interfero gravitational wave observatory in — ly. = * Asthe masses orbit and accelerate, their gravitational intensity fluctuates, generating Waves, rd in all directions, traveling freely through spacetime at the speeg ofl gating through the universe ht Gravitational waves radiate outwa intensity weakens with distance from the source propa! Union 4) ‘5 4 hie © Wave i Characteristics of GWs , ; nas: The characteristics of GWs depend on the system's properties, such as: © Masses of the objects—— © Orbital period and frequency * Eccentricity of the orbit: Eccentricity & is a measure of the amount by which an object deviates from a Berfect en e=0 Circular orbit ) 7 e=l Parabolic trajectory U/ Lr) e>l Hyperbolic trajectory a € > O
