Laser Micrometer

Single-Slit Diffraction?

Single-Slit Diffraction
1. You have been asked to measure the width of a slit in a piece of paper. You mount the paper 80 centimeters from a screen and illuminate it from behind with laser light of wavelength 633 nanometers (in air). You mark two of the intensity minima as shown in the figure, and measure the distance between them to be 17.9 millimeters
Express your answer in micrometers, to three significant figures.
2.If the entire apparatus were submerged in water, would the width of the central peak change?
a. The width would increase.
b.The width would decrease.
c.The width would not change.

here's the link to the page

(1) In single slit diffraction ,for position of minima ,path difference d sine theta =n*wavelength, where n is order of minima.In the figure shown 17. 9 mm is total distance between 3 rd minima on either side.
therefore 2y=17.9
y=8.95 mm
sine theta=tan theta=y/screen distance'D'
d sine theta= d * y/ screen distance 'D

d * y/ screen distance 'D= 3 wavelength
d =3wavelength*D / y
=3*633*E-9*0.8/8.95*E-3
=169.743 micro meter.
(2)width in water= width in air / refractive index of water
hence width in water will decrease ( choice b correct)

'

Digimatic Micrometer Digimatic Micrometer $162.99 No programming needed to start measuring all the way down to .00005" (50 millionths!). User programmable to do all sorts of comparative measurements . . . compare multiple pieces to one original or set the desired dimension as zero and compare all pieces to that. Full black-filled thimble and sleeve markings so can be used even if the battery runs out. Instant conversion from inch to millimeters - better than any chart. Mfg: Mitutoyo SPECS: 5¾" (14.6cm) long x 2-5/8" (6.7cm) high. Carbide tipped measuring faces. Reads 0-1" (2.5cm) 0-25mm. Accurate to .00005" (.0013mm). W/case.

Ocular Micrometer $58.94 High Quality Content by WIKIPEDIA articles An ocular micrometer is a glass disk that fits in a microscope eyepiece that has a ruled scale, which is used to measure the size of magnified objects. The physical length of the marks on the scale depend on the degree of magnification. A microscope (from the Greek:, mikros, small and, skopein, to look or see ) is an instrument to see objects too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy. Microscopic means invisible to the eye unless aided by a microscope. Author: Surhone, Lambert M./ Tennoe, Mariam T./ Henssonow, Susan F. Binding Type: Paperback Number of Pages: 74 Publication Date: 2010/08/16 Language: English Dimensions: 6.00 x 9.02 x 0.18 inches

Mitutoyo Ball Style Micrometer Mitutoyo Ball Style Micrometer $164.95 The Mitutoyo Ball micrometer features a ball anvil set at right angles to the micrometer head. This allows the handloader to use this tool for measuring wall thickness of brass tubing etc. Measures to .0001"" and features a ratchet stop. Micrometer spindle is carbide faced. Scales are easy to read. Mfg: Mitutoyo

Mitutoyo 1 Inch Micrometer Mitutoyo 1 Inch Micrometer $82.95 A 1"" micrometer is used for measuring case expansion and outside diameters of virtually anything up to 1.0000"". The shaft and anvil on this micrometer are carbide faced. Measures to .0001"". Mfg: Mitutoyo

Micrometer Adjustable Torque Wrench $54.99 Bikemaster Micrometer Adjustable Torque Wrench Micrometer-type sleeve allows accurate pre-set torque values to be set Reversible ratchet head Available with 3/8” or 1/2” Sq. Dr 3/8" Sq. Dr Marked range (5-80 ft lbs) 1/2" Sq. Dr Marked range (10-150 ft lbs)

Sinclair/Starret Case Neck Micrometer Sinclair/Starret Case Neck Micrometer $159.95 The Sinclair Case Neck Micrometer is built around a Starrett micrometer head capable of measuring in .0001inch increments.This tool is designed specifically for handloaders to accurately measure case neck wall thickness. The micrometer head and anvil are completely adjustable so the handloader can measure the neck wall thickness right up to the junction of the case neck and shoulder. These adjusting features plus the ratchet control built into the micrometer head allow the user to zero the tool to suit their own feel and their own needs. The tool is mounted to a stainless steel base and allows the handloader to have both hands free to use when measuring brass. The micrometer head is mo Mfg: Sinclair International

Air Venturi Rear Sight, Micrometer Adjustable $35.99 Fits Air Arms MPR & Crosman Challenger Micrometer adjustments for windage & elevation

Micrometer - Mechanical Digital, 0-1'' $54.95 ? Quality import at a value price ? Swiss style micrometer with mechanical digital readout ? Carbide faces ? Friction thimble for precise, repeatable measurement ? Thermal shields for dimensional stability while measuring ? 0-1'' range, 0.0001'' graduationBy Storm by Central.

Sinclair/Wilson Micrometer Seater Top Sinclair/Wilson Micrometer Seater Top $39.95 The Sinclair Micrometer Top allows the handloader to convert existing Wilson seaters to micrometer seaters. The top is constructed of stainless steel and is graduated in increments of .001 inch. To use remove the existing seating stem from your Wilson Seater cap and install in the Sinclair Micrometer Top. Now you are ready to make quick and easy changes to your cartridge's overall length. The top utilizes your existing seater stem or you can purchase an additional stem. Stem is not included. Mfg: Sinclair International

Sinclair Digital Case Neck Micrometer Sinclair Digital Case Neck Micrometer $224.99 Our Digital Case Neck Micrometer will measure neck thickness to 0.0001 inch on cases from 17 caliber to 50 BMG. The Sinclair designed anvil is the same as on our MIC-3 Case Neck Micrometer. The digital micrometer head powers on and zero sets with the push of a button and the large friction barrel makes it easy to achieve a very repeatable feel. The micrometer head features inch to millimeter selection power off after 5 minutes of inactivity- roll thr friction barrel to re-activate without re-zeroing data output and absolute or relative measuring. The Sinclair stand positions the anvil and micrometer head at a stable and comfortable position for repetitive measurements and the display can Mfg: Sinclair International

Mendoza Micrometer Sight, 11mm Dovetail $23.99 Open rear sight Micrometer windage and elevation adjustments Fits any gun with an 11mm dovetail Securely attaches with dual clamping screws Lightweight aluminum Durable, anodized finish

Sinclair Trimmer Micrometer Attachment Sinclair Trimmer Micrometer Attachment $89.95 Wilson Case Trimmers owners can easily add the new Sinclair Micrometer Attachment to their case trimmer. The micrometer has clear crisp engravings and can be locked in place after being set. Adjustable in increments of .001inch and can be adjusted to handle cases ranging from 22 Hornet to 416 Rigby. Great addition for those handloaders switching back and forth between different trim lengths. Mfg: Sinclair International

Fowler Disc Brake Micrometer. Each $63.97 Manufacturer: Fowler. Each. Features Benefits: Measuring range: .300-1.300 Graduations: .001 Carbide tipped anvil faces Includes measuring standards Jaw depth: 3-1/2 Customers also search for: Discount Disc Brake Micrometer, Buy Disc Brake Micromete

General Tools General Tools 1 in Micrometer 102 $16.53 1? micrometer Ideal for general usage, training program, automotive work, hobbyists, etc Features 0-1? range, satin finish frame with decimal equivalents Packed in storage box complete with instructions and standards Brand #: General Tools 102 UPC: 038728441034 Keywords: micrometer hobby

Fowler Measuring Caliper Micrometer Mechanics Set. Each $84.19 Manufacturer: Fowler. Each. Features Benefits: 0-1in. outside micrometer 6in. EZ read steel rule Storage case 0-6in, One-rev shockproof dial caliper with .001in. graduations Customers also search for: Discount Measuring Caliper Micrometer Mechanics Se

Replacement Instrument Batteries Cr2450 Replacement Micrometer Batteries $4.95 CR2450 Replacement Micrometer Battery CANNOT BE SHIPPED OUT OF THE U.S. This item can only ship UPS Ground within the continental United States. Mfg: Starrett

Redding Case Trimmer W/ Micrometer Redding Case Trimmer W/ Micrometer $149.99 This case trimmer has all the same great features as the standard Redding Trimmer with the addition of a case length micrometer and push button chuck lock. The 2400 trimmer also utilizes a new extended cast iron frame which enables it to handle the lastest long action cartridges and longer old time classic as well. Trims cases up to three and one fourth in length. The micrometer is easy to read and makes quick and precise case length adjustments in increments of .001 inch. Redding's push button chuck lock simplifies case loading and unloading and faciliates perfect alignment of the case between the collet and pilot. Includes six case pilots - .22 cal 6mm .25 cal .270 cal 7mm and and Mfg: Redding

Starrett Standard 1" Outside Micrometer Starrett Standard 1 Outside Micrometer $191.99 This is the same 1"" micrometer you see in professional machine shops all over the world. This Starrett micrometer measures to .0001"" with superb repeatble accuracy. Ratchet stop mechanism make it easy for any user to repeat measurements and carbide anvil faces insure a lifetime of accurate measuring. The micrometer comes with an instruction booklet for reading and adjusting the instrument an adjustment wrench and plastic case. The 1"" micrometer and 6"" caliper are the basic measuring tools for reloader and shooters. Made in the USA. Mfg: Starrett

Laser Micro QC 1

A laser cavity has a flat mirror and a spherical mirror with radius of curvature of 40 cm. The mirrors are sep

A laser cavity has a flat mirror and a spherical mirror with radius of curvature of 40 cm. The mirrors are separated by 20 cm. The flat mirror is partially transparent, while the spherical mirror is perfectly reflecting. An output of 2 mW at a wavelength of 0.543 um (micrometer, green) is emitted by the laser.
a) Demonstrate that the cavity is stable.
b) What is the half angle of the beam divergence (in radians)?
c) An opaque screen with a circular hole of radius a is placed at a distance of 40 cm from the flat mirror. A total power of 1 mW passes through the hole. Calculate the radius of “a” of the hole. Assume that the center of the hole coincides perfectly with the optical beam axis.

For a stable mode, the wavefront curvature of the mode has to match that of both mirrors, thus it is flat on the flat mirror. Thus take the origin of the z-coordinate on the flat mirror since the beam waist is there. The radius of curvature of the wavefront satisfies

R(z)=z [1 + (zR/z)^2 ],

where zR =k w0^2/2 is the Rayleigh length in terms of the beam radius w0 at the waist. Now, when z=L, R(z)=2 L. Thus

2 L =L[1+ (zR/L)^2 ]

Hence zR=L=20 cm, so that w0= sqrt(2L/k)=sqrt(Lλ /π )=.0186 cm. The cavity is stable because the real part of 1/w0^2 is positive (a negative value describes a field that grows away from the axis , which would clearly be unstable).

Use
w=w0 sqrt(1+z^2/zR^2),

set z=40 cm, that will give w at the location of the disk. Let

I(r) = I0 exp(-2 r^2/w^2).

I leave it to yuo to determine I0 in terms of the total power.
The power passing through a hole of radius a is

P = 2π∫ (r=0 to a) I(r) r dr

= I0 (π /2)w^2 [ 1-exp(-2 a^2/w^2)].

You solve this for a.