Beamsplitter

beamsplitter cube

Beamsplitters are used to split or combine beams of light. Plates are used for most laser applications as they exhibit low absorption. Cubes are a convenient, protected form for low power applications. The performance of a beamsplitter is mainly dependent on the coating specifications.

BEAMSPLITTER SPECTRUM PROPERTIES
BEAMSPLITTER PLATE Broadband Wavelength Beamsplitter plates can be used with high power lasers. When using beamsplitter plates, it is important to bear in mind that the two partial beams travel different optical paths. The optical paths depend on the incident angle and the thickness of the plates.
Single Wavelength
BEAMSPLITTER CUBE Broadband Wavelength Compare with beamsplitter plates, beamsplitter cubes have the following advantages:

-Identical path lengths for both the reflected and the transmitted beams

-The transmitted beam is neither display nor deflected

-Stable and compact

-Easy operation

-Easy to mount / align

Single Wavelength
PENTA BEAMSPLITTER CUBE Broadband Wavelength
630-680nm
T/R: 20%/80% ±5%Single Wavelength
The penta beamsplitter is composed of a penta prism and a wedge. Like the beamsplitter cube, it has the following properties:

-The transmitted beam is neither display nor deflected

- Stable and compact

-Easy operation

POLARIZING BEAMSPLITTER CUBE Broadband Wavelength The prism can be used as polarizers, beamsplitters, or beam combiners. The output beam, which is parallel to the input beam, is called a p-polarized beam while the orthoganal output beam is defined as the s-polarized beam.
Single Wavelength

 

 

1 BEAMSPLITTER PLATES CAPABILITY

ATTRIBUTE STANDARD PREMIUM
MATERIAL BK7 BK7
DIMENSION TOLERANCE ±0.1mm ±0.02mm
THICKNESS TOLERANCE ±0.1mm ±0.02mm
FLATNESS Per 25.4mm λ/4 @ 632.8nm Per 25.4mm λ/10 @ 632.8nm
SURFACE QUALITY 60-40 scratch and dig 10-5 scratch and dig
PARALLELISM <20 arc seconds <5 arc seconds
T/R T=(Ts+Tp)/2,

R=(Rs+Rp)/2

T/R=50/50, 80/20, 70/30, 90/10, 60/40

±5% @ λ c or λ b

T=(Ts+Tp)/2,

R=(Rs+Rp)/2

T/R=50/50, 80/20, 70/30, 90/10, 60/40

±3% @ λ c or λ b

COATING λ c: Single wavelength, λ b: Broadband wavelength

BS plate

 

 

2 BEAMSPLITTER CUBES CAPABILITY

ATTRIBUTE STANDARD PREMIUM
MATERIAL BK7 BK7
DIMENSION TOLERANCE ±0.2mm ±0.1mm
FLATNESS Per 25.4mm λ/4 @ 632.8nm Per 25.4mm λ/10 @ 632.8nm
SURFACE QUALITY 60-40 scratch and dig 20-10 scratch and dig
T/R 50/50 ± 5% 50/50 ± 2%
BEAM DEVIATION <3arc minutes <30arc seconds
COATING Specified wavelength or T/R Specified wavelength or T/R

BS cube

 

 

3 POLARIZING  BEAMSPLITTER (PBS) CAPABILITY

ATTRIBUTE STANDARD PREMIUM
MATERIAL BK7, SF2,H-ZF3 BK7, SF2,H-

ZF3

DIMENSION TOLERANCE ±0.2mm ±0.1mm
SURFACE QUALITY 60-40 20-10
BEAM DEVIATION <3 arc minutes <30 arc seconds
EXTINCTION RATIO Narrow band>500:1, >1000:1

Boardband>300:1, >100:1

PRINCIPAL TRANSMITTANCE Tp>95%, Ts<1% Specify
PRINCIPAL REFLECTANCE Rs>99%, Rp<5% Specify
COATING AR on all input and output surfaces BPS. Coating on hypotenuse (broadband wavelength: 450-680, 650-850, 900-1200, 1200-1550, 1500-1610nm, etc.)

SPECIALITY:  Photonchina are able to provide High Power PBS of various wavelength, which can bear great laser power (~ 15J / cm2 @ 1064nm, 20ns, 20Hz), as well as high extinction ratio.

 

 

A polarizing beamsplitter (PBS) or polarizing beam splitting prism, is an optical element for separating horizontal and vertical polarization of light.

 

Structure of PBS

PBS structure

Shown above, it is coated with a multilayer interference film on the slope of the right-angle prism, and then glued into a cubic structure to transmit the incident P-polarized component and the S-polarized component.

 

Features of Polarization Beamsplitting Products:

Separate horizontal polarization and vertical polarization of a beam of light;

The ratio of the transmittance of P to S light is greater than 1000, and the P light transmittance is above 90%.

Small stress, high extinction ratio, good image quality and small beam deflection angle.

The wavelength covers the 420-1600 nm region.

Used in such occasion as polarizing, analyzing, light intensity adjustment etc. It is a key component in projection system, imaging system, optical instrument and optical measurement system.

 

Limitations of PBS

It should be noted that the working effect of the polarization beam splitting prism, is wavelength limited. Further, PBS is only an element for roughly selecting polarization, and if the precision demand of polarization is high, a Glan Thompson Polarizer or the like can be used.

 

4. NON-POLARIZING BEAMSPLITTER (NPBS)  CAPABILITY

ATTRIBUTE STANDARD PREMIUM
Material:   N-BK7; Fused Silica
Dimension X×Y:   1×1mm~25.4×25.4mm
Dimension tolerance: ±0.1mm ±0.03mm
Parallelism: <20 seconds <5 seconds
Clear Aperture: 85%
Surface Quality: MIL60-40 MIL20-10
Flatness(per 25.4mm): λ/4@ 632.8nm    λ/10@ 632.8nm
T/R(for random porlarization)T=(Ts+Tp)/2;R=(Rs+Rp)/2: 50/50±5%  50/50±2%
Bevel(face width×45°) : Protective bevel or specified by customer
Coating: Narrow band or 400~700; 700~1100; 1100~1600(nm)
Available beam splitting ratio 8/2, 7/3, 6/4, 5/5, 4/6, 3/7, 2/8, 1/9

 

Non-polarizing beamsplitter (high power NPBS) is a kind of special polarizing beamsplitter. It makes the p-polarization component and S- polarization component of incident light have similar spectral characteristics.

 

Structure of NPBS

Non polarizing beamsplitter

The optical coatings have been designed to hold both the s and p-polarization components to the same ratio of reflection-to-transmission over a specific laser wavelength region. This means that they will not change the state of polarization of the incident beam. All input and output surfaces are coated with a high efficiency anti-reflection coating.

 

Features of Non-Polarization Beamsplitting Products:

  • The ratio of horizontal polarization and vertical polarization of incident light should be maintained as much as possible after splitting by the NPBS.
  • The degree of separation for optical properties of P and S is less than 5%, Dispersion is low and the color neutrality is good.
  • The wavelength covers 400-1600nm, which is widely used in interferometers and various imaging instruments.
  • Non-polarization beamsplitter is very useful for randomly polarized light as it is specially designed to minimize the polarization effect.

 

Photonchina can provide both narrow-band and broadband NPBS.