I. Introduction

Lecture 1, 9/2/99. Observational astronomy
Last modified 11/12/99 3:01PM
We consider the spectra of astronomical objects, and their faintness, to demonstrate the necessity of observations at all wavelengths, the requirements on the sensitivity of detectors, and the useful range of spectral and angular resolution.

II. Geometrical optics

Lecture 2, 9/7/99. Rays, paraxial rays, thin mirrors and lenses
Last modified 9/29/99 11:23 AM
Here we review paraxial geometrical optics, introducing the thin lens and lensmaker's equations, and discussing sign conventions, real and virtual images and objects, and magnification.

Lecture 3, 9/9/99. Conic section mirrors
Last modified 9/22/99 7:10 PM
We review here the general properties of conic section surfaces, used universally in telescopes.

Lecture 4, 9/14/99. Introduction to analytical ray tracing
Last modified 9/27/99 12:23 PM
Lecture 5, 9/16/99. Ray-surface intersections and ray propagation
Last modified 9/22/99 7:26 PM
Here you will learn how to do geometrical optics with no approximations; or, rather, how to teach a computer to do so.

Lecture 6, 9/21/99. Computerized ray tracing
Last modified 9/22/99 7:40 PM
This is an introduction to RayTrace 5.0, a computer program you will be using in your homework to study optical systems.

Lecture 7, 9/23/99. On-axis geometrical aberrations
Last modified 9/23/99 9:52 PM
The aberrations of a spherical mirror are derived, characterizing the first third-order blurring mechanism, spherical aberration.

Lecture 8, 9/28/99. Off-axis geometrical aberrations
Last modified 9/28/99 6:53 PM
Oblique-incident rays and a paraboloidal mirror are used to obtain expressions for three other third-order aberrations: coma, astigmatism, and distortion.

Lecture 9, 9/30/99. Telescopes: in general, and two-mirror telescopes
Last modified 9/29/99 11:49 PM
Lecture 10, 10/5/99. Aberration compensation for spherical primaries: the Schmidt camera
Last modified 10/5/99 7:06 PM
The most common astronomical telescopes, those of the Cassegrain and Schmidt families, are discussed: mountings, design parameters, aberration correction and performance.

Lecture 11, 10/7/99. Cameras
Last modified 10/7/99 4:27 PM
The auxiliary optics for making images with telescopes are discussed: Petzval field curvature, field lenses, stops, reimaging optics, cameras.

III. Physical optics

Lecture 12, 10/12/99. The scalar theory of diffraction
Last modified 10/12/99 1:31 PM
The scalar theory of far-field diffraction of electromagnetic waves is introduced.

Lecture 13, 10/14/99. The diffraction-limited telescope: diffraction from a circular aperture
Last modified 10/14/99 9:13 PM
Here we give an important example of the application of this theory: the image formed by a circular aperture.

Lecture 14, 10/19/99. Gaussian beam propagation
Last modified 10/19/99 3:37 PM
Approximation of a diffraction-limited beam by a Gaussian profile gives rise to a method for optical design similar to the paraxial theory of geometrical optics.

Lecture 15, 10/21/99. Diffraction-limited telescopes
Last modified 10/19/99 11:42 PM
Diffraction patterns are the same for broadcast and reception, for a given diffraction-limited antenna. We are now in a position to describe radio telescopes.

Lecture 16, 10/26/99. Radio interferometers
Last modified 10/26/99 5:53 PM
We will develop the Van Cittert-Zernike theorem, a principle closely related to those used to describe scalar far-field diffraction, and use it to describe the synthesis of an image from measurements made by several independent telescopes.

Lecture 17, 10/28/99. Seeing, and its suppression
Last modified 11/2/99, 2:51 PM
Here we discuss briefly the nature of image blurring by atmospheric turbulence and describe the simplest adaptive-optical techniques used  to overcome seeing.

IV. Detectors and noise

Lecture 18, 11/2/99. Photodetectors
Last modified 11/4/99 11:07 PM
This class of detectors includes the most sensitive sensors presently available, and is therefore of the greatest utility to astronomers.

Lecture 19, 11/4/99. Shot noise
Last modified 11/4/99 5:01 PM
The simplest noise process in photodetectors, that due to absorption of photons and production of electrons and/or holes, is discussed.

Lecture 20, 11/9/99. Johnson noise
Last modified 10/29/99 11:50 PM
We will carry out the derivation of noise from thermally-generated electrons and holes. This represents one extreme of the photon probability distribution; such interesting related phenomena as photon bunching are discussed.

Lecture 21, 11/11/99. Incoherent detection with photodetectors.
Last modified 11/2/99 3:42 PM
A discussion of photoconductive gain enables one of shot noise in photocurrents, and allows the derivation of the ideal background-limited sensitivity of short-wavelength, incoherent detection.

Lecture 22, 11/16/99. Coherent detection with photodetectors
Last modified 11/2/99 3:42 PM
Here we discuss the other detection method in wide use, heterodyne detection, and derive the short-wavelength ideal quantum-noise-limited sensitivity of coherent detection.

Lecture 23, 11/18/99. Background fluctuations and quantum noise
Last modified 11/2/99 3:42 PM
The effects of photon bunching are included to complete the expressions for sensitivity of ideal coherent and incoherent detectors, and to enable comparison of the sensitivity achieved by the two techniques. Sensitivity of coherent preamplification is considered to illustrate the origin of quantum noise.

V. Instruments for photometry and spectroscopy

Lecture 24, 11/23/99. Broadband filters and photometry
Last modified 11/2/99 3:42 PM
The tools of photometry, particularly multilayer dielectric filters, are described in general terms here.

Lecture 25, 11/30/99. Interference filters
Last modified 11/2/99 3:42 PM
Lecture 26, 12/2/99. Fabry-Perot interferometers
Last modified 11/2/99 3:42 PM
These devices, and their relatives, provide the highest-sensitivity method for obtaining spectral-line images of celestial sources.

Lecture 27, 12/7/99. Diffraction gratings
Last modified 12/6/99 11:59 PM
The most sensitive instruments for measurement of the spectra of compact celestial objects are based upon various implementations of gratings.

Lecture 28, 12/9/99. Spectrometers
Last modified 12/13/99 10:37 PM
Here we discuss cross-dispersion, echelles and fiber-fed grating spectrographs, and offer two concluding, complete conceptual design examples for FPI and grating spectrometers.