Starting from an understanding of basic phenomena of light and materials known as spontaneous emission and induced emission, the instructor explains principles of lasers configured from inverted distribution and an optical resonator. The instructor introduces the concept of coherence effective for characterizing properties of laser light generated, and makes clear the difference with normal light. Then the instructor will explain the coherent state formed as a result of a material interacting with coherent light. Students start from an isolated two-level system as a suitable material system, and are then introduced to a density matrix to expand to a many-body system of sets. We also cover relaxation phenomena such as T1, T2. We finally go over the features of many types of lasers, and classify them to introduce real, applied examples.
After gaining an understanding of the basic principles of laser oscillation based on space mode, the difference between lasers and normal light, and the basics of coherent interaction, students will study the quantum state of coherent materials that cannot be realized with normal light sources. Students will also gain an understanding of the operating principles and features of all kinds of lasers, acquiring knowledge about their applications.
spatial mode, spontaneous emission, induced emission, population invesion, optical resonator, coherence, density matix, ultra-short pulse
|Intercultural skills||Communication skills||Specialist skills||Critical thinking skills||Practical and/or problem-solving skills|
A lecture note with several blanks is provided in advance. Instead of black board, descriptions are directly written on screen by a pen tablet computer. Hearing the explanation, students fill in the blanks and complete the lecture note.
|Course schedule||Required learning|
|Class 1||absorption and emission of light||Einstein’s theory of spontaneous and induced emission|
|Class 2||principle of a laser||population inversion and optical resonator|
|Class 3||character of laser oscillation||rate equation of laser oscillation|
|Class 4||Coherence of laser light||time and space coherence|
|Class 5||coherent interaction between light and two level system||Rabi oscillation|
|Class 6||motion equation of density matrix||optical Bloch equation|
|Class 7||continuous wave and ultra-short pulse laser||mode locking|
|Class 8||character and classification of various lasers||solid-state, liqid and gas lasers|
lecture note is distributed.
Introduction to laser physics, Koich Shimoda, Iwanami.
Thequantum theory of light, Loudon, Oxford.
Learning achievement is evaluated by a final exam.