Acousto-Optic Frequency Shifter

Acousto-Optic Frequency Shifter

Doppler shifts the frequency of input light by an amount equal to the RF drive frequency but is optimized specifically for this purpose. Typically our frequency shifters will use the anisotropic interaction of the slow shear.

Doppler shifts the frequency of input light by an amount equal to the RF drive frequency, but is optimized specifically for this purpose. Typically our frequency shifters will use the anisotropic interaction of the slow shear mode in tellurium dioxide (TeO2). Applications such as interference-based optical techniques require a high extinction ratio between the diffracted and undiffracted beam; this can be achieved with a high-quality optical finish to minimize optical scatter.

We offer standard products with frequency shifts of 40-350 MHz, many of which can be operated in double-pass configurations. In addition we can design for custom frequency shifts where required. Frequency shifters are fabricated using high quality TeO2, grown and polished in-house, for lowest insertion loss and excellent power handling. Other acousto-optic materials are available and may be more appropriate for some applications.

TeO2 based frequency shifters are highly efficient acousto-optic devices, requiring very low drive power to achieve the desired frequency shift. Our designs consume minimal power (generally<100 mW power draw), often allowing us to package the driver with the AOFS for a more compact and power-efficient solution.

Our standard model are below:

Model Wavelength Operating Frequency Active Aperture Driver Optical Material
I-M110-3C10BB-3-GH27 300-400 nm 110 MHz 3.0 mm Crystal quartz
AOMO 3080-125 (97-01598-01) 415-900 nm 80 MHz 2.0 mm Tellurium dioxide
AOMO 3100-125 (97-03035-01) 440-850 nm 100 MHz 1.5 mm Tellurium dioxide
AOMO 3200-125 (97-03036-01) 470-690 nm 200 MHz 1.5 mm Tellurium dioxide
I-FS040-1.5S2C-3-GH83 532 nm 40 MHz 1.5 mm Tellurium dioxide
I-FS040-1.5S2C-1-GH66 532 nm 40 MHz 1.5 mm Integrated Tellurium dioxide
I-FS080-3S2E-1-GH39 633 nm 80 MHz 3 mm Integrated Tellurium dioxide
I-FS080-3S2E-3-LG5 633 nm 80 MHz 3 mm Tellurium dioxide
I-FS040-1.5S2E-3-LE15 630-680nm 40MHz 1.5mm 97-05301-01 Tellurium dioxide
I-FS040-2.5S2E-M-PP3 630-680nm 40MHz 2.5mm 97-05301-01 Tellurium dioxide
I-FS040-2S2E-1-GH66 630-690 nm 40 MHz 2 mm Integrated Tellurium dioxide
AOFS 4040-191 (97-03099-02) 633-1064 nm 40 MHz 2x6 mm Tellurium dioxide
I-FS080-2S2G-3-LV1 1064 nm 80 MHz 2 mm Tellurium dioxide
I-M040-2C8J-3-GH84 1550 nm 40 MHz 2 mm AMTIR
I-M040-2C8B1-3-GH84 1900-2100 nm 40 MHz 2 mm AMTIR

1. I-FS040-1.5S2E-3-LE15

  • Device: AO Frequency shifter
  • Interaction material: Tellurium Dioxide
  • RF Drive Frequency: 40MHz
  • Operational wavelength: 630 - 680nm
  • Reflectivity per surface: < 0·2%
  • Minimum optical aperture: 4 x 2·0 mm (horizontal and vertical)
  • Active aperture: 1·5mm (vertical)
  • Transmission: > 95% @ 633nm
  • Maximum diffraction efficiency: > 90% @ 633nm
  • Polarisation of input beam: Linear and horizontal with respect housing
  • Polarisation state of 1st order: Linear and orthogonal to input and zero order beams
  • Zero to 1st order polarisation extinction ratio: > 100:1
  • Amplitude Modulation of Diffracted-Order: < -40dB (@40MHz & 80MHz)
  • Output Configuration: Diffracted & undiffracted beams split about Input direction.
  • Separation (0 to Diffracted-order): > 2º
  • RF Drive Power: > 100mW
  • Input Impedance: 50W
  • RF connector: SMA Bulkhead Jack
  • RF driver 97-05301-01 (AODR 1080HE-AD-1.0)

2. I-FS040-2.5S2E-M-PP3

  • Device: AO Frequency shifter
  • Interaction material: Tellurium Dioxide
  • RF Drive Frequency: 40MHz
  • Operational wavelength: 630 - 680nm
  • Reflectivity per surface: < 0·2%
  • Minimum optical aperture: 4.0 x 3.0mm (horizontal and vertical)
  • Active aperture: 2.5mm (vertical)
  • Transmission: > 95% @ 633nm
  • Maximum diffraction efficiency: > 90% @ 633nm (TBC)
  • Polarisation of input beam: Linear and horizontal with respect housing
  • Polarisation state of 1st order: Linear and orthogonal to input and zero order beams
  • Zero to 1st order polarisation extinction ratio: > 100:1
  • Amplitude Modulation of Diffracted-Order: < -40dB (@40MHz & 80MHz)
  • Output Configuration: Diffracted & undiffracted beams split about Input direction.
  • Separation (0 to Diffracted-order): > 2º
  • RF Drive Power: ≤ 120mW
  • VSWR: TBC
  • Input Impedance: 50
  • RF connector: MHF SMT receptacle
  • RF driver 97-05301-01 (AODR 1080HE-AD-1.0)

STBR Series Free Space AO Frequency Shifters

The STBR Free Space Acousto-Optic Frequency Shifter (AOFS) with RF driver is used to modify the frequency of the optical beam. Due to a Doppler shift, the frequency of the diffracted first order optical beam in the AO modulator or AO frequency shifter is shifted in frequency (wavelength) by the acoustic carrier frequency (wavelength). If the incident acoustic wave is introduced in the direction of the incident optical wave, the laser frequency shifts towards the higher side. If the incident acoustic wave is introduced in the opposite direction of the incident optical wave, the laser shifts toward the lower frequency side.

Our STBR AO Frequency Shifter are below:

Model # Spectral Range (nm) DE up to (%) Frequency Shift (MHz) Active Aperture (mm) Material
AMF-90-2-2.1 1000-2200 15 90 1.0 AM
AMF-55-1.3 1000-2200 80 55 2.0 AM
AMF-100-1.3 1000-2200 80 100 2.0 AM
GEF-40-10 2000-12000 75 40 2.0 Ge
GEF-60-1.5 2000-12000 75 60 1.5 Ge
GEF-80-20 2000-12000 70 80 1.0 Ge
GPF-250-100 590-1000 60 250 0.75 GaP
GPF-650-225 590-1000 50 650 0.18 GaP
GPF-1000-500 590-1000 40 1000 0.076 GaP
GPF-1500-1000 590-1000 10 1500 0.076 GaP
GPF-1700-500 590-1000 30 1700 0.076 GaP
IPF-200-50 1000-1600 40 200 0.75 InP
IPF-400-200 1000-1600 35 400 0.50 InP
IPF-600-200 1000-1600 30 600 0.18 InP
IPF-800-300 1000-1600 20 800 0.076 InP
IPF-1000-350 1000-1600 15 1000 0.076 InP
IPF-1300-400 1000-1600 10 1300 0.076 InP
LNF-2500-1000 400/830 20 2500 0.076 LiNBO3
LNF-3500-1000 400-630 5 3500 0.076 LiNBO3
QZF-80-20 200-4500 75 80 1.0 SiO2
QZF-150-30 200-4500 75 150 0.75 SiO2
QZF-210-40 200-4500 75 210 0.5 SiO2
TEF-200-50 400-1600 60 200 0.75 TEO2
TEF-270-100 400-1600 60 270 0.75 TEO2
TEF-540-200 400-1600 40 540 0.18 TEO2
TEF-600-400 400-1600 40 600 0.18 TEO2
TEF-1000-300 400-1600 40 1000 0.076 TEO2
TEF-1700-350 400-1600 15 1700 0.076 TEO2

For the associated RF drivers, please refer to “RF Drivers for STBR series” through the link at bottom

AOFS for Fibre Sensors M040-8J-F2S

A compact fibre-coupled acousto-optic frequency shifter ideal for use in interferometric fibre sensor systems such as Mach-Zehnder and laser Doppler configurations.

Available in frequencies from 35 to 45MHz and either up-shift or down-shift. This device operates over a broad wavelength range making it the first choice frequency shifter for distributed sensor networks.

- Polarization insensitive

- Choice of wavelengths, 1450 to 1650nm

- Choice of operationg frequency, 35 to 45MHz

Spec ificati on

Interaction Material Chalcogenide Glass
Wavelength 1520 to 1610nm
Polarisation Dependant Loss None
Polarisation Mode Dispersion None
Insertion Loss <3.0dB
Extinction Ratio (1st order on/off) >50dB
Rise-Time / Fall-Time 110ns
Frequency 40MHz
VSWR <1.2:1 (50Ω input impedance)
RF Power 0.2W typical
Frequency Shift -40MHz, down shift
Fibre Type Single mode, 2m
Fibre Connectors FC/PC, Seiko-Geiken

Opt ions

  • Frequency: 35 to 45MHz
  • Frequency Shift: Up shift
  • Wavelength Range: Centred on 1500 to 1580nm
  • Fibre Type: Polarisation maintaining, multimode
  • Fibre Connectors: Pig-tails for splicig, FC/APC