1 Mw Green Laser Distance

A laser cavity has a flat mirror and a spherical mirror with radius?

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.

I don't know how to answer this question. But this is what I notice.

Since the radius of curvature is 40 cm, the focal length is 20 cm. And they are separated by 20 cm, so the focal point of the curved mirror is located on the flat mirror.

New 50 mw Green Beam Laser pointer free shipping $9.46 New 50 mw Green Beam Laser pointer free shipping

(HOT sell+ Cheap) --5mW Newest Laser Pointer Green Light Pen Beam 5 mw+Box FreeShipping $23.09 5mW Newest Laser Pointer Green Light Pen Beam 5 mw

5mW Newest Laser Pointer Green Light Pen Beam 5 mw+Box FreeShipping $10.91 5mW Newest Laser Pointer Green Light Pen Beam 5 mw+Box : high quality green laser pointer, Output power: 5mW

New Stylish 30mW 30 mW 532nm Green Beam Laser Pointer Pen with battery and box packing $7.06

Newest 5mW 5 mW 532nm Green Beam Laser Pointer Pen+free shipping $8.35 Newest 5mW 5 mW 532nm Green Beam Laser Pointer Pen+free shipping

Free shipping Stylish 5mW 5 mW 532nm Green Beam Laser Pointer Pen $8.42 Free shipping Stylish 5mW 5 mW 532nm Green Beam Laser Pointer Pen

New 50 mw Green Beam Laser pointer $9.45 The blue laser beam beams ultra bright and can be seen miles away.

UT391 Laser Distance Meter $81.4 This laser distance meter is specially designed for users. It is high-precision and multi-functional.It can measure distance, area and volume, pythagorean laws can also be used to measure indirectly.This is light, easy to use and reliable.It provides accurate measurement easier and faster.This is usable in construction, upholster, property, traffic, fire-fighting, gardening, urban planning, water monitoring, electrical power overhaul and much more.Best replacement for traditional measuring instrument such as measuring tape.Specification:Measurement distance: Range: 0.1 m to 60m/Accuracy: positive/negative 1.5mm; Range 4 inches to 197 feet/Accuracy: positive/negative 0.06 inchesMeasurieng units: meter, inch, foot, 4 types unit displayArea, Volume calculations: Has m2/ft/m3/ft3 unitsIndirect measurement using Pythagoras: Supports 2.3 indirect measurementsAddition/Subtraction: YesContinuous measurement: YesMin/Max distance tracking: YesDisplay illumination and multi-line display: Maximum 4 displaysDatum option: Can choose front edge or end piece edge as datumBuzzer indication: YesBacklight display: White, can auto switch offAuto Bias Technology: Supports for external calibrationError indicator: Display error codeData hold: AutoHistory measurement records: 20Data clear: YesBattery indicator: High,Midium,LowLaser auto switch off: after 0.5 minAuto instrument switch off: after 3 minWaterproof: IP54Laser type: 635nm, less than 1mC Class IIBattery life: greater than 5000timesKey life: greater than 1 million timesOperating temperature: 0 to positive 40 degrees Celsius (positive 32 to 104 degrees Fahrenheit)Storage temperature: negative 10 to positive 60 degrees Celsius (positive 14 to positive 140 degrees Fahrenheit)Weight: 258gDimension: 122*43*28 mmPackage:1*UT391 Laser Distance Meter1*Carry bag1*Screwdriver1* Battery

Whoesale HIGH-POWER 350mW 532NM GREEN LASER POINTER PEN China Post Freeshipping $50.53 350 mw green laser pen,hotsale !!!

MULTI PRE PROG. LASER FX $112.5 4.9 mW Green Laser Light Effects System w/3 Operation modes

30mw Green star Laser pointer of Continuous Wave and continuous output ,within box MOQ:1 pcs $8.42 Green Laser pointer 1.Beam Distance:500-6000m 2.working time over 5000 hours 3.Features:Continuous Wave 4.CE and ROHS

Eliminator Lighting TARANTULA 4.9 mW Green Laser Light Effects System with 3 Operation modes $157.95 4.9 mW Green Laser with compact plastic case. Preset Geometric Patterns. Multiple patterns may be created by manual control. 3 Operation modes Auto Manual and Sound Active. Fan Cooled. Includes Power Adapter (120V/60Hz DC 9V UL).

REAL 50mW,laser pen,laser pointer,532nm Green Beam Laser Pen,free shipping $15.68 1. Real power size of 50 mW ; 2. Slim size of normal pen

New 30 mw Green Beam Laser pointer $8.74 30mw,laser pointer

New 100 mw Green Beam Laser pointer $14.74 100mw,LASER POINTER

Longridge Golf Ball Laser Distance Finder $109.99 Weight 165kg. Batteries required: 1 x CR2032 (not included). EAN/MPN/UPC/ISBN: 5060158890163. Effective objective diameter 24mm. Eyepiece focusing. Size H6.9, W11, D3.9cm. Semiconductor laser (harmless to eyes) ranging method. LCD display. The Range Finder is adapted with the latest digital circuit design and optical system that is superior to other models in lens quality and reliability. It features 6 x magnification, multi-coated optics, +/- 1 yard accuracy, easy finger-tip operation and through-the-lens distance display. The Range Finder is an advanced laser range finder system that rapidly provides an accurately measured distance out to 600m. By Longridge.

Ultrasonic Distance Measure Laser Point (Yellow) $17.06 - Laser will not be influenced by weather, temperature, etc.- With laser piont, you can get exact distance.- Measures distance from 1.5 feet to 60 feet.- Area, volume, addition, subtraction calulation.- The laser emitted from the unit is visible laser of 650nm wavelength.- Accuracy: ¡À 0.5% ¡À 1.- Resolution: 0.01M or 1/12 inch.- LCD with backlight.- Working frequency: 40kHz.- Range 2 to 60ft.- Brand new product with high quality.- Important Notice: Customers should be sure whether their countries are allowed to import Red lasers before purchasing. If you're unsure of whether your country allows these kinds of products, we recommend you to contact the custom for confirmation. We will not be responsible for losses due to customs confiscation.

Ultrasonic Laser Point Pointer Distance Meter Measurer $24.99 Description:Press READ to turn on the unit, the laser point light on, the distance betwwen the laser distance measurer and the point you measured apears.To find the area and volume of a room, measure the length and press X/=,measure the width, then press X/=,then the square icon and the data of area appears, measure the height and press X/= the cubic icon and the data of volume appears.The initial unit is metric, hold the SET key 3 second, the unit can switch between METRIC and IMPERIAL.The laser distance meter turns itself off if no key is pressed within about 30 seconds.Size of the laser measurer: ~12.2 x 6 x 3.3cm(L*W*D)Weight: 117.3gSpecification:measurer power by 1 x 9V battery (will not be included here)Unit of measurement feet or meters.Accuracy 0.5%+1 digit(2-60ft)Working frequency 40KHzWorking temperature 32 degreeF to 109.4 degreeFRange 2 to 60 ft(0.55 to 18.288m)Specifications are typical: individual units might varySpecifications are subject to change and improvement without notice.Class II laser product output<1mw.Package included instruction manual.

Newest 5mW 5 mW 532nm Green Beam Laser Pointer Pen, free shipping ,Mini order 1 pc $8.63 Full check before shipped. 30 days guarantee.

Account limit of 2098 requests per hour exceeded.

200 MW Green laser pointer

Green Laser Pointers - Which One Should I Choose?

Just by typing in the word "laser pointer" into google's search engine, you will find hundreds of laser pointer companies out there. Some have very attractive websites with very high prices. Some laser pointers offer the same functions and power but are much cheaper. It's all very confusing especially when you don't understand what all the terms mean. You're about to spend a good amount of money on a laser pointer, the least you should is do some research before choosing the right laser and right company for your needs.

The first thing you will notice about high powered green laser pointers is they are always categorized by power. This is the number with "mW" at the end. mW stands for milli-watts and is 1/1000 of a watt, that is, 1000mW is 1W. You will also see another number associated with green laser pointers. This number has "nm" at the end. This stands for nano-meters and is used to measure wavelength. You really don't have to look into this number too much as all green laser pointers have a wavelength of 532nm. Pretty much, when you see 532nm, you should automatically think of the color green.

Now, lets focus on power. This is probably the most important factor because the more power you buy, the more money you spend. Yes, power is expensive! You need to ask yourself, what are you buying this laser pointer for? I think I can categories this into 3 types of lasers.

The first type, you're looking to buy something for everyday use. You're a teacher, professor, or someone always doing presentations in large groups. You are looking to use the green laser pointer as a "pointer". Good, I can make the decision for you now. Get a 5mw green laser pointer. While you could buy something more powerful, I wouldn't suggest getting anything over 20mW if pointing is all you will be doing. 5mW is for small classroom pointing, 20mw is for longer distance pointing as in an auditorium.  Now, I'm talking about real laser pointers, that is, don't buy from ebay or any auction sites. Their advertised output is usually fake. If you buy a 5mW, you'll probably end up with a 1-2mW green laser. You can search the term "Skylasers" in google, they are a good reputable company.

Now, the second type is looking for a visible beam green laser pointer. First question, are you looking to burn or melt anything with it? If you answer is no, stick with a green laser pointer between 20mW to 80mW. During the day, these lasers have a very bright end dot (the laser beam is not visible). Realize that you will not find a laser pointer with a visible beam during the day. At night, however, a 20-80mw green laser is very bright! Yes, amazingly bright! This is where I ask, how much do you plan on spending? The more power you buy, the brighter the laser pointer. On a personal note, I would recommend a 40 - 60mW green laser pointer if all you want is a bright beam. The 20mW is still slightly dim for me. 40mW to 60mW green laser pointers go for around $100-$150. If you have the money, go for the 80mW, you will notice the difference in brightness. I just think 40mW - 60mW is plenty bright though.

If you are looking to burn and melt with this laser, you need something above 100mW. Want to see laser pointers in action? Simple, go to youtube and search for "lasers". You will find green laser pointers from various companies lighting cigarettes, popping balloons, etc. There are some very cool videos out there. The question now is, what do you want to burn? Again, the more power you have, the faster your laser will burn and melt. You can buy green laser pointers with more then 500mw these days that could cost you a pretty penny. It's really up to you as to how much you want to spend. If burning is your thing, look around for reliable companies and compare prices. Buy something you are comfortable with spending.

There are several laser pointer forums out there that can be very resourceful to you. Stick with www.laserpointerforums.com, www.photonlexicon, and www.candlepoweredforums.com. These forums have a good following and members are generally very eager to answer your questions. I suggest staying away from www.lasercommunity.com, this forum is very tightly monitored and is run by a laser company. They do not allow members talking about other laser companies...

About the Author

Green laser pointers have been a hobby of mine for a number of years. I hope my articles are useful to you and good luck in your search for the perfect laser pointer!

If you are a laser enthusiast like me and is interested in learning about the physics behind lasers, check out how lasers work!