Awesome product , I’m going to get a PM400 with S425C-L sensor 👍

Thanks for the great video. I was looking for this! Does the position of the sensor need to be perpendicular to the laser? If the position of the laser cannot be moved, is there a component to adjust the tilt of the sensor?

@thorlabs

2 жыл бұрын

We're glad you found the video helpful! The answer to your alignment question depends on several factors specific to your application, including whether measurements of relative or absolute power are required and if your setup can tolerate back reflections. In general, it's good to keep in mind that power sensors are calibrated with the light at normal incidence and that the power reading will vary as the beam's angle of incidence changes. If only relative measurements of power are required, which is often the case, it's not critical to align the laser perpendicular to the sensor. In fact, it's common practice to orient the sensor at a small angle (≤10°) to the beam, since this reduces back reflections in the optical system. However, it IS important to ensure that the same configuration is used for every relative power measurement. When absolute power measurements are required, there are considerably more demands on the measurement, and a specialized power sensor, such as an integrating sphere ( www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=4688&YVI=2 ), may be preferred. Something else to keep in mind when making power measurements is that some power will be lost due to angle-dependent Fresnel reflections from the surface of the power sensor, as well as from any diffusers or windows incorporated into the sensor package. Another thing to check is that the effective spot size of the beam on the sensor is smaller than, and contained within, the active area of the sensor. Note that when the laser is not perpendicular to the sensor, the cross sectional area of the beam will be larger than if the beam were normally incident. If this is not taken into account, it may result in the beam being clipped by an aperture or extending off the active area of the sensor. There are a few options for stably and repeatably altering the angle between the power sensor and the laser beam. One option is to use an angled optic mount, such as the SM1L03T ( www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=215&pn=SM1L03T&YVI=2 ). Another option is to use an angle block ( www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=5585&YVI=2 ). If you think of a topic you'd like to see demonstrated, let us know!

@hiro-xo8jf

2 жыл бұрын

@@thorlabs Thank you for your kind answer. I only relative measurements of power are required. I have several lasers that I want to measure, one of which has a beam diameter that varies from 13mm to 26mm. the S121C has a larger beam diameter than the sensor, so I plan to use the LA1274-A to adjust the focal length. I would be grateful if you could tell me how to check and adjust the focus of the lens to make sure it is illuminating the sensor.

@thorlabs

2 жыл бұрын

@@hiro-xo8jf A technique we find helpful when reducing the spot size on the power sensor is to use the lens to focus the beam to a location that's farther along the optical axis than the sensor's position. When this is done, the beam is converging at the sensor position, but the beam does not focus on the sensor. (It's important not to focus the beam on the sensor ( www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=10741&tabname=Beam%20Size&YVI=2 ).) Using this approach, as long as the beam diameter is smaller than the input aperture in front of the sensor, you can be sure the diameter of the beam is not overfilling the sensor. If you have additional questions, please contact tech support ( www.thorlabs.com/supportcontact.cfm ), and they'll provide information tailored to your particular application.

Hi, can this optical power meter be used to measure irradaince? If so, how? Thank you.

@thorlabs

3 жыл бұрын

The optical power (Watts) measured by an optical power meter is one of the values needed to calculate the average irradiance (Watts/cm^2) delivered to the sensor. To approximate this value, divide the power reading by the beam's cross sectional area at the sensor. Some optical power meters, including the PM400 shown in this video, can automatically calculate and display irradiance after the beam parameters are entered (see Sections 3.9 and 3.10 of the manual).

Will this measure power from infrared laser? And will it work for Infrared led diode(750-1100nm) ? I understand the IR waves from led diode goes all over the place, just want to measure how much power in the direction of the sensor. And which tool would you recommend, most basic please. Thanks.

@thorlabs

3 жыл бұрын

The power meter shown being set up in this video is compatible with a range of optical power sensors, including a variety used to detect IR light over the wavelength range you mention. However, when choosing a power sensor for an application, there are a number of variables to consider in addition to the wavelength of light incident on the power sensor. These variables include additional details about your source and application, as well as your measurement requirements. There is a webinar ( kzread.info/dash/bejne/nZamsNCGYb21XdY.html ) that provides some background information and guidance for choosing power sensors for different applications, including measuring the power emitted by highly divergent sources. Another webinar ( kzread.info/dash/bejne/qYNo2bWEmNLAiMo.html ) includes discussion on operating precautions, practical use of photodetector power sensors, and a photodetector selection guide. Tech Support (techsupport@thorlabs.com) would also be happy to discuss the particulars of your application with you and recommend compatible power sensors, as well as any additional components that may be needed. Thanks for your comment, we'll keep it in mind as a suggestion for expanding our power measurement demonstration videos!

@qigong1001

3 жыл бұрын

@@thorlabs Thanks for the thorough response. I will check the links!

Hi Amtuthaa, Please provide a full video of the PM100D power meter to better utilize this device. Is any storage facility available to receive power in the PM100D

@thorlabs

2 жыл бұрын

Thank you very much for this topic recommendation! It's great to know you'd be interested in a demonstration of the PM100D that goes into greater detail, and it's now on our list. The PM100D is provided with a power supply and a power cord customized for the country in which the device will be operated. If the power supply needs to be replaced, please contact Thorlabs Tech Support (techsupport@thorlabs.com ), and we'll be happy to help.

@GyanDeepVermaPEE

2 жыл бұрын

@@thorlabs thank you for your response

if one wants to measure supercontinuum power, since it is a broadband, what wavelength should one choose on the power meter ?

@thorlabs

Жыл бұрын

There are two options for using the PM400 power meter to measure the power from a broadband source, with the choice depending on the wavelength range of your source spectrum and the responsivity of your power sensor. The power measurement provided depends on both the responsivity of the sensor, as well as the spectrum of the light source. If the power sensor’s responsivity is flat over the wavelength range of your light source, a convenient option is to configure the PM400 for a wavelength within your source’s spectrum. Then, the PM400 would use a single responsivity value to provide a power value. This technique would be a good option, for example, if the source emits light from 200 to 900 nm and a S415C thermal power sensor head is used, since the sensor’s absorbance is approximately flat over this wavelength range (www.thorlabs.com/drawings/ee136629cc6e35d3-2596B20D-5056-8D76-1303D39D0D58AAC2/S415C-SpecSheet.pdf). If the power sensor’s responsivity is not flat across the wavelength range of the light source, it is possible to upload a spectrum of the source to the PM400 console. If you need to do this, please reach out to Tech Support ( techsupport@thorlabs.com ) for assistance.

@naveed3619

Жыл бұрын

@@thorlabs Thanks for the reply. I am measuring the power of the supercontinuum source (500-1700 nm), so the best option for me would be to upload the spectrum to the console. I will contact thorlabs support.