Author Affiliations
1State Key Laboratory for Modern Optical Instrumentation, Center for Optical & Electromagnetic Research, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Zijingang Campus, Hangzhou 310058, China2Ningbo Research Institute, Zhejiang University, Ningbo 315100, Chinashow less
Fig. 1. The 3D view (a) and the top view (b) of the present ultra-high-resolution on-chip spectrometer. Schematic configurations of the ultra-high-Q resonator (c) and the wideband resonator (d). (e) The principle of the spectrum retrieved process.
Fig. 2. (a) Microscope images of the fabricated ultrahigh-resolution spectrometer. Zoom-in views of the grating coupler (b), the wideband resonator (c), the Euler bend (d), and the heater on ultra-high-Q resonator (e).
Fig. 3. (a) Measured spectrum response of the fabricated 10-channel wideband resonators. (b) Measured spectral responses at the through/drop ports of the ultrahigh-Q resonator; Inset: the resonance peak. (c) The spectral response of the ultrahigh-Q resonator when applying different heating power. (d) The resonance wavelength as the heating power Ph increases. (e) The calibrated wavelength-power map. As an example, the arrow indicates the peak wavelength λi dropped by the i-th cascaded wideband resonator when the heating power Ph is 30 mW.
Fig. 4. Retrieved spectrum for a given spectrum with a single peak when using the present on-chip spectrometer as well as a commercial OSA with a resolution of 0.02 nm. (a) The peak wavelength is 1546.61 nm locating at channel C1. (b) The peak wavelength is 1549.45 nm locating at channel C4. (c) The peak wavelength is 1552.67 nm locating at channel C7.
Fig. 5. Normalized retrieved spectrum with double peak input at channel C7. (a) (1552.627, 1552.632) nm, (b) (1552.024, 1552.624) nm, (c) (1552.643, 1552.646) nm.
Fig. 6. Measured results for the spectrum generated from a commercial fiber Bragg filter.
Ref | Configuration | Footprint (mm2) | Resolution (nm) | Bandwidth (nm) | Bandwidth/resolution | CMOS compatible | ref.6 | AWG | 64 | 0.2 | 1537-1557 | 100 | Yes | ref.7 | AWG+ring | 9 | 0.1 | 1542-1569 | 270 | Yes | ref.9 | EDG+SCD | ~100 | 9 | 600-2000 | 155.6 | No | ref.8 | EDG | 9 | 0.5 | 1556-1566 | 20 | Yes | ref.10 | EDG+ring | 2 | 0.1 | 1483-1493 | 100 | Yes | ref.11 | Micro-donut | ~100 | 0.6 | 1540-1610 | 116 | Yes | ref.19 | PhC | 5.67×10–3 | 10 | 1510-1590 | 8 | Yes | ref.20 | Disordered PhC | 1.25×10–3 | 0.75 | 1500-1525 | 33.3 | Yes | ref.21 | CQD | ~100 | 2-3 | 390-690 | 150 | No | ref.18 | Chirped-grating | 448 | 0.3 | 580-650 | 233 | Yes | ref.13 | FTS | 1 | 3 | 1522-1578 | 18.7 | Yes | ref.22 | FTS+ring | 0.2 | 0.47 | 1526-1616 | 191.5 | Yes | ref.14 | DFT | 1.8 | 0.2 | 1550-1570 | 100 | Yes | ref.15 | SHFT | >1 | 0.017 | 1550-1550.22 | 12.9 | Yes | ref.16 | HSDFT | 13.87 | 0.0011 | 1550-15562 | 10714 | Yes | ref.17 | Nanowire | ~0.1 mm | 5 | 500-750 | 50 | No | This work | Cascade ring+
Euler ring | 0.35 | 0.005 | 1545.8-1555.5 | 1940 | Yes |
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Table 1. Comparison of some typical spectrometers reported.