Author Affiliations
1School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China2Key Laboratory of Opto-Electronics Information Technology, Ministry of Education, Tianjin 300072, China3College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China4College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China5Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Chinashow less
Fig. 1. Silicon waveguide devices based on SOI have low two-photon absorption and low BOX absorption in the short-wavelength mid-IR band
[22, 25-26] Fig. 2. Silicon waveguides in the short-wavelength mid-IR band. (a) Measurement result of optical loss of the TE
0-mode strip (left) and rib (right) silicon waveguides
[42]; (b) Scanning electron microscope (SEM) images of the silicon waveguide fabricated with the MPW service
[27]; (c) SEM image of the SMW cross section
[44]; (d) Schematic of the subwavelength-grating-cladding suspended slot waveguide
[45] Fig. 3. Silicon grating couplers in the short-wavelength mid-IR band. (a) SEM image of the shallow-etched uniform grating coupler
[53]; (b) Schematic of the polysilicon/silicon grating coupler
[40]; (c) SEM image of the focusing subwavelength grating coupler fabricated with the MPW service
[27]; (d) Measurement results of the ultra-thin focusing subwavelength grating coupler
[55] Fig. 4. Silicon micro-resonators in the short-wavelength mid-IR band. (a) SEM image of the racetrack microring resonator
[60]; (b) Schematic picture of the suspended membrane ring resonator
[44]; (c) Microscope image of the tunable microring resonator
[61]; (d) SEM image of the microdisk resonator with the subwavelength grating structure
[63] Fig. 5. Silicon multiplexing/demultiplexing devices in the short-wavelength mid-IR band. (a) The transmission spectrum image of different channels (left) and microscope image (right) of the AWG
[69]; (b) Microscope image of the echelle grating
[68]; (c) Schematic of the silicon multi-mode multiplexing/demultiplexing devices
[71]; (d) Measured bit error rate (BER) of the silicon multi-mode multiplexing/demultiplexing devices as a function of the received optical signal-to-noise ratio (OSNR)
[71] Fig. 6. Nonlinear optical waveguide devices in the short-wavelength mid-IR band. (a) Wavelength conversion across more than one octave based on FWM
[74]; (b) SCG based on the SOI waveguide
[77]; (c) Schematic of the Kerr frequency comb generation in the microring resonator
[82]; (d) Spectrum and intracavity power of the KFC based on the Si/Ge waveguide
[82] Fig. 7. Optoelectronic waveguide devices in the short-wavelength mid-IR band. (a) Cross-sectional schematic diagram of the active region of the p-i-n diode phase-shifter
[83]; (b) Optical microscope image of the MZM
[84]; (c) Schematic of the racetrack microring resonator-enhanced WSi nanowire photodetector. The red line indicates the waveguide on which the WSi nanowire is integrated
[91]; (d) SEM image of the cross-section of the Zn
2+-implanted Si waveguide photodiodes
[92] No. | Wafer | Wavelength/
μm
| Optical loss/
dB·cm−1 | Waveguide type | Ref. | 1 | SOI | 2.2 | 0.6 | Strip | [40]
| 2 | SOI | 2 | 1.00±0.008 | Rib | [41]
| 3 | SOS | 2.08 | 1.4 | Strip | [43]
| 4 | SOI | 2.02 | 1.9±0.2 | Rib | [42]
| 5 | SOI | 2.02 | 3.3±0.5 | Strip | [42]
| 6 | SOI | 2.25 | 7.9 | Suspended slot | [45]
|
|
Table 1. Characteristics of the silicon waveguides in the short-wavelength mid-IR band
No. | Wafer | Etch depth
/nm
| Structure | Wavelength/μm | Bandwidth
/nm
| Efficiency
/dB
| Ref. | 1 | SOI | 70 | SEGC | 2.15 | 160 (3 dB) | −5.2 | [53]
| 2 | SOI | 240 | SEGC | 2.1 | 90 (3 dB) | −3.8 | [40]
| 3 | SOI | N/A | FSGC | 2.255/2.331 | 38/54 (1 dB) | −5.9/−5.7 | [54]
| 4 | SOI | 70 | FSGC | 2.36 | 85 (3 dB) | −7.77 | [27]
| 5 | SOI | 150 | FSGC | 2.2 | 115 (1 dB) | −7.1 | [55]
|
|
Table 2. Characteristics of the silicon grating couplers in the short-wavelength mid-IR band
No. | Wafer | Q factor
| FSR
/nm
| Structure | Ref. | 1 | SOI | 75000 | 3.9 | Microring | [24]
| 2 | SOI | 17000 | 4.5 | Microring | [5]
| 3 | SOS | 11400 | N/A | Racetrack microring | [60]
| 4 | SOI | 11000 | 4.47 | Microring with p-type doping | [5]
| 5 | SOI | 8100 | N/A | Suspended membrane microring | [44]
| 6 | SOI | 1520 | 12 | Racetrack microring | [61]
| 7 | SOI | 800 | 40 | Subwavelength grating microdisk | [63]
|
|
Table 3. Characteristics of the silicon micro-resonators in the short-wavelength mid-IR band
No. | Wavelength
/μm
| Insertion loss
/dB
| Crosstalk
/dB
| Structure | Ref. | 1 | 2 | 6 | −15.7 | AWG | [69]
| 2 | 2.1/2.3 | High | < −16 | EG | [68]
| 3 | 2.2 | 4 | −16 | AWG | [68]
| 4 | 2 | < 5 | < −18 | DC | [71]
| 5 | 2 | 1.2 | −18.83 | MMI | [70]
|
|
Table 4. Characteristics of the silicon multiplexing/demultiplexing devices in the short-wavelength mid-IR band
No. | Wafer | Wavelength/μm | Speed
/Gbit·s-1 | ER
/dB
| ME | Structure | Ref. | 1 | SOI | 2.16 | 3 | 23 | 0.12
V·mm
| MZI | [83]
| 2 | SOI | 2 | 20 | 5.8 | 0.268
V·mm
| MZI | [23]
| 3 | SOI | 2 | 3 | 2.3 | N/A | MRR | [23]
| 4 | SOI | 2 | 80 | N/A | N/A | MZI | [84]
| 5 | SOI | 2 | N/A | N/A | 0.17 nm/mW | MZI | [89]
| 6 | SOI | 2 | N/A | N/A | 0.1 nm/mW | MRR | [89]
|
|
Table 5. Characteristics of the silicon-waveguide-integrated modulators in the short-wavelength mid-IR band
No. | Type | Wavelength
/μm
| Responsivity
/mA·W-1 | Dark current
/μA
| Ref. | 1 | GaInAsSb p-i-n photodiode | 2.29 | 0.44 | 1.13 | [93]
| 2 | GeSn p-i-n photodetector | 2 | 93 | 171 | [94]
| 3 | Silicon−graphene waveguide photodetector | 2 | 70 | N/A | [97]
| 4 | Superconducting nanowire single photon detectors | 2.1 | N/A | N/A | [91]
| 5 | Zn+ implanted Si waveguide photodiode
| 2.2-2.4 | 87±29 | < 10 | [92]
| 6 | Si+-implanted Si-wire waveguide photodetector
| 2.2-2.3 | 10 | < 1 | [98]
| 7 | Silicon photodiode | 2 | 0.3 | < 1 | [99]
|
|
Table 6. Characteristics of the silicon-waveguide-integrated detectors in the short-wavelength mid-IR band