Measuring instrument
Laser Focal Profiler (LFP)
LFP measures the intensity distribution in a
diffraction-limited focal spot with a 40 nm resolution.
The world's first nanoscale beam profiler that reveals
the performance and aberrations of any laser equipment.
- Overview
- Specifications
- Original paper
Overview
Laser focal profiler (LFP) is a precise measuring instrument for the intensity distribution near the laser focal spot. LFP is the world's first instrument and unique product to make it possible to measure the ultra-fine focal spot formed by high NA (numerical aperture) lens.
The intensity distribution near the laser focal spot is a key performance indicator of many laser micro-/nanotechnologies. It evaluates the spatial resolution of laser microscopes, the efficiency of laser beam machining, the record density of optical data storage, the spring constant of force measurement systems with optical trapping, performance of microscope objective lenses.
A beam profiler using a CCD/CMOS camera as a commercial product is available for intensity profiling of the cross-section of the propagating laser Beam. However, it is difficult to apply directly for the laser focal spot with an microscope objective lens due to the limited spatial resolution originated to a large pixel size, which is more than a micron at minimum. To apply this profiler to a focal spot smaller than the pixel size, the focal spot needs to be magnified with optics and imaged onto the detector. However, this magnification method may induce unwanted aberrations; it is difficult to align and requires that the magnification optics have a higher 𝑁𝐴 than those used for focusing the laser beam.
The knife-edge method is another in situ technique that has been suggested but is not commercialized for a small laser focal spot because of several reasons as sharpness of the knife-edge, artifact and so on.
LFP utilizes gold nanoparticle of 40-nm size and achieve to measure the focal spot with the only several hundred nanometers with high NA lens (~1.4) with high precision.
Feature
- Only one
- High resolution (40nm; the size of a nanoparticle)
- Applicable to High NA focusing lens ( ～ 1.4)
- Compact sensor with 26 mm height which can operate on a microscope stage
- No adjustment is required.
- Principle with accurate measurement（Perfect aberration-free, minimized artifact）
- 3D measurement
Application
- Laser Microscope
- Laser machining
- Laser fabrication
- Optical memory
- Optical tweezers
- Optical setup overall
- Variety of microscope objective lenses including liquid immersion lenses
Specifications
Part List
- LFP sensor including consumable probe head
- Scanner (If you selected)
- Controller
- Laptop PC
- Cables
LFP sensor
| Sensor Model | LFP-UV-111100 | LFP-VIS-166145 | LFP-NIR-166145 |
|---|---|---|---|
| Laser wavelength | 200 nm ~ 400 nm | 400 nm ~ 1100 nm | 1000 nm ~ 1700 nm |
| Probe | Gold nanoparticl 40 nm | Gold nanoparticl 40 nm | Gold nanoparticl 4 0nm |
| Number of Probe (in the area of beam illudiation, Φ100μm） |
> 5 | > 5 | > 5 |
| NALFP | 1.11 | 1.66 | 1.66 |
| NAcutoff | 1.00 | 1.45 | 1.45 |
| Photosensitivity (V/nW) (typ.) | TBD | TBD | TBD |
| Cutoff frequency of Amp (Hz) | 160 | 160 | 160 |
| Gain of Amplifier | 100M | 100M | 100M |
| Size (mm) | Φ30 H31 | Φ30 H26 | Φ30 H26 |
| Weight (g) | 55 | 50 | 50 |
Scanner
| Scanner Model | TBD XYZ | TBD XY |
|---|---|---|
| Axis | x/y/z | x/y |
| Drive type | Piezoelectric element | Piezoelectric element |
| Stroke (μm) | 120/120/60 | 120/120 |
| Resonat frequency (Hz) at 50g load |
155/155/155 | 155/155 |
| Repetablility (nm) | ±5/±5/±5 | ±5/±5 |
| Poisition sensor | Capacitive sensor | Capacitive sensor |
| Aperture (mm) | Φ30 | Φ30 |
| Size (mm) | □100 H26 | □100 H26 |
| Weight (kg) | 0.5 | 0.6 |
Controller
| Controller | TBD XY | TBD XY | TBD NA |
|---|---|---|---|
| Output port for scanner drive | Drive x 3ch(SMB) Position sensor x 3ch(TJM) |
Drive x 2ch(SMB) Position sensor x 2ch(TJM) AO(16bit,-10V to 10V) x 1ch, (TJM) Pulse output x 1ch (TJM) |
AO(16bit,0V to 10V) x 3ch(TJM) Pulse output x 3ch (NBC) |
| Feedback control type | PI Analog | PI Analog | N.A. |
| Input sensor port | 1ch (BNC) | 1ch (BNC) | 1ch (BNC) |
| Input dynamic range | 16bit | 16bit | 16bit |
| PC communication bus | USB | USB | USB |
| Power supply | AC100 ～ 120V / AC200 ～ 240V selection |
AC100 ～ 120V / AC200 ～ 240V selection |
AC100 ～ 120V / AC200 ～ 240V selection |
| Power comsumption | 100 VA | 100 VA | 50 VA |
| Size (mm) | W236×D388×H140 | W236×D388×H140 | TBD |
| Weight (kg) | 5.4 | 5.4 | TBD |
Original paper
Taisuke Ota
“Laser focal profiler based on forward scattering of a nanoparticle”
Opt. Commun. 411, 59-64 (2018)
