Diffraction

Diffraction – The Central Maximum

• Here is the pattern you will see. Notice in figure 2 that there are several bright spots and dark areas in between. The spot in the middle is the BRIGHTEST and thus the CENTRAL MAXIMUM. We call these spots FRINGES.
• 2-rasmga e'tibor bering, ular orasida bir nechta yorqin dog'lar va qorong'u joylar mavjud. O'rtadagi nuqta ENG YORQINLIK va shuning uchun MARKAZIY MAKSIMUM. Biz bu dog'larni FRINGES deb ataymiz.
• Notice we have additional bright spots, yet the intensity is a bit less. We denote these additional bright spots as ORDERS. So the first bright spot on either side of the central maximum is called the FIRST ORDER BRIGHT FRINGE. Figure 1 represents the intensity of the orders as we move farther from the bright central maximum.
• E'tibor bering, bizda qo'shimcha yorqin dog'lar bor, ammo intensivlik biroz kamroq. Biz bu qo'shimcha yorqin nuqtalarni BUYURTLAR deb belgilaymiz. Shunday qilib, markaziy maksimalning har ikki tomonidagi birinchi yorqin nuqta FIRST ORDER BRIGHT FRINGE deb ataladi. 1-rasm, biz yorqin markaziy maksimaldan uzoqroqqa o'tayotganimizda, buyurtmalarning intensivligini ifodalaydi.

• Figure 1

• Figure 2

Diffraction – Orders, m Diffraktsiya - Buyurtmalar, m

• We use the letter, m, to represent the ORDER of the fringe from the bright central.
• Yorqin markazdan chekka TARTIBIni ifodalash uchun m harfidan foydalanamiz.

• Central
• Maximum

• First Order
• Bright Fringe
• m = 1

• First Order
• Bright Fringe
• m = 1

• Second Order
• Bright Fringe
• m = 2

• Second Order
• Bright Fringe
• m = 2

Diffraction – Bright Fringes

• The reason you see additional bright fringes is because the waves CONSTRUCTIVELY build.
• Qo'shimcha yorqin chekkalarni ko'rishingizning sababi to'lqinlarning KONSTRUKTİV tarzda shakllanishidir.
• There is a difference however in the intensity as you saw in the previous slide.
• Oldingi slaydda ko'rganingizdek, intensivlikda farq bor
• As you can see in the picture, the BLUE WAVE has to travel farther than the RED WAVE to reach the screen at the position shown. For the BLUE WAVE and the RED WAVE to build constructively they MUST be IN PHASE.
• Rasmda ko'rib turganingizdek, ko'rsatilgan holatda ekranga etib borish uchun KO'K TO'LQIN QIZIL TO'LQINDAN uzoqroqqa borishi kerak. KO'K TO'LQIN va QIZIL TO'LQIN konstruktiv tarzda qurilishi uchun ular FAZADA bo'lishi kerak.